Cesareans

Readers of this blog may notice that I talk about cesareans a lot. This is true; although not my main focus for the blog, it is definitely a common topic here.

So why do I talk so much about cesareans?

I talk about cesareans a lot because a high cesarean rate has major implications for maternal/fetal health on a large scale.

It's also because cesareans tend to be shrugged off as "no big deal" by many people, even promoted as "minor surgery" or "better" for the baby or mother by some healthcare professionals. Yet research simply doesn't support this.

So I want to bring attention to the fact that cesareans actually do have significant health risks and implications.

And I want to particularly bring attention to the fact that women of size are being disproportionately exposed to the significant risks of cesareans compared to other women, and that this exposure is often unnecessary.

Public Health Concerns vs. Personal Experiences

One concern that I have on this blog is that some people misinterpret writings on birth issues as a personal criticism of their birth stories. But that's not what's intended here at all.

I speak about cesareans and associated risks from a public health perspective, not as a criticism of any one person's birth story.

Some women hear any criticism of birth statistics as a criticism of their own personal choices and experiences. No, your birth is your birth, and we need less mommy-war judgments about these things. No one is telling you that you are less of a mother or less worthy as a person if you had a cesarean, or that you should feel badly for having an epidural or whatever. Your individual experience is your individual experience and no one should judge you for that.

However, we do need to be able to separate out our personal experiences from the public health implications of high rates of birth interventions.

On a global scale, the increase in cesarean rates matters, and has critical implications for public health issues.  

A cesarean can be a wonderful, life-saving thing. It can also be a great emotional and physical relief if you've had a long, hard labor, if your baby is in distress, or if there is some other complication that makes a cesarean sensible. In some situations, a cesarean does offer more benefits than risks.

On the other hand, if there are too many cesareans, done on too wide-spread and casual a basis, then public health will be impacted in a negative way. As a recent press release from the Childbirth Connection notes (my emphasis):

Cesarean section increases the likelihood of at least 25 adverse health  outcomes, according to the broadest systematic examination of the health consequences of cesarean section...For the woman, these risks include infection, hysterectomy, and death. For the infant, risks include newborn respiratory problems and chronic illnesses such as asthma and diabetes. Risks also include life-threatening complications for both mothers and babies in future pregnancies... 

“C-sections can be life-saving in a small proportion of emergency situations. For other types of complications the risks of major abdominal surgery may outweigh the benefits,” said Maureen Corry, Executive Director of Childbirth Connection and co-chair of the Maternity Action Team. “But today, too many low-risk women who are the least likely to benefit from cesareans are having them. That means these women and their babies face unnecessary risks and avoidable harm. This best evidence report clarifies what is at stake for mothers and babies and why the U.S. must work diligently to reduce the c-section rate, especially among low-risk women.”

Cesareans are greatly over-utilized today in many countries, not just the U.S. Although writers tend to discuss this issue from a U.S.-centric perspective, the truth is that many countries have high cesarean rates. The public health implications of this issue, therefore, are world-wide.

But because individually, most cesareans go well, many care providers don't take their potential risks seriously enough. Nowadays, far too many women are being exposed to cesarean risks for non-life-threatening reasons.

There is a common perception in the public that if a cesarean is done, it must have been necessary to save the mother or the baby. Yet a woman's risk for a cesarean is not just due to medical factors like fetal distress or excessive bleeding, but also on where and with whom she gives birth.

Research has increasingly found that women face vastly different risks for cesarean in different hospitals, even within the same economic area and with similar risk factors. In other words, the same woman may go to hospital A and be many times more likely to experience a cesarean than if she had gone to hospital B. Or be much more likely to need a cesarean if she sees provider C instead of provider D. This is called "practice variation" and raises a whole host of ethical questions because it implies that cesareans are being done for reasons other than saving lives.

Practice variation flies in the face of the belief that if a woman has a cesarean, it must have been "necessary" or that cesareans usually result in healthier babies. Sometimes a cesarean is needed, but far too often a cesarean results from questionable indications or as a result of a cascade of interventions that end up causing more harm than good.

Sadly, the path that leads to cesarean for nearly 1 in 3 American women (and far higher in some areas ─ some American hospitals have 50%, 60%, and even higher cesarean rates) frequently involves factors more complicated than saving lives.

So yes, cesareans can be life-saving and necessary. However, when over-utilized, they may actually present more risk than benefit, especially in the long-term. And that's why we talk about it.  It is a critical public health discussion that must be taken more seriously all over the world.

Maternal Obesity and Cesareans: 
An Epidemic of Over-Use

This issue of high cesarean rates is particularly important for women of size, because the rate of complications from cesareans in "obese" women is even higher than in average-sized women.

Obese women have even higher risks for blood clots, hemorrhage, infections, anesthesia issues, and wound complications from cesareans than other women do. You would think that clinicians therefore would be anxious to avoid cesareans in obese women. Yet our cesarean rate today is extremely high.

How high? Exact numbers depend on the study, when it was done, and its target population.

For example, Weiss 2004 showed a cesarean rate of nearly 50% in women with a BMI over 35...and that was only in first-time mothers. What would it be if repeat cesareans were added into the total? What would it be if they considered only those with a BMI over 40?  Or over 50?

Brost 1997 found a total cesarean rate of 40.5% in women with a BMI over 40, with a rapid elevation in cesarean rate as BMI went up from there.  By the time BMI was 52 or more, the total cesarean rate was over 70%. And that was in 1997─the rate is likely even higher in these hospitals now because the overall cesarean rate has gone up considerably since then.

The cesarean rate in women of size is probably headed even higher because many clinicians have a distorted sense of risk around our pregnancies, and therefore a very low threshold for surgical intervention. More and more obese women are being pushed into cesareans these days, often without even a chance for labor. Fat women are also being denied the opportunity for Vaginal Birth After Cesarean (VBAC) in many practices, further increasing our cesarean rates.

Yet it wasn't always this way. In the past, the cesarean rate among women of size was significantly lower than it is today, often similar to the rates of non-obese women. In fact, a 1978 study in the American Journal of Obstetrics and Gynecology noted:

"In agreement with most other studies, no significant increase in Cesarean sections or operative forceps delivery was noted in [the obese group.]"

If the cesarean rate was significantly lower in the past for obese women, it means that most fat women can give birth vaginally under the right conditions, and that a high cesarean rate is not an inevitable outcome of obesity. 

Instead, many of the cesareans in women of size today may be “iatrogenic”—that is, influenced more by the attitudes and management protocols of the care providers than by the woman’s size.

If the research is examined closely, it suggests that labor management choices often leads to the high cesarean rates in obese women. Abenhaim 2011 found that doctors used more interventions in the labors of high-BMI women and were much quicker to move to a cesarean in this group. When these interventions were controlled for, the difference in cesarean rates was "markedly attenuated."

High induction rates play a central role too. Usha Kiran 2005 found a 19% c-section rate in obese women with spontaneous labor, but a 41% c-section rate in obese women whose labors were induced. Green 2011 found that when induction of labor was controlled for, the difference in cesarean rates between obese and non-obese women virtually disappeared.

Even in the very heaviest women, the cesarean rate can vary dramatically, confirming the role of labor management. Garabedian 2011 found a 56% cesarean rate in women with a BMI of 50 and above. In contrast, however, Homer 2011 found about half the cesarean rate (30%) in a group of women of the exact same size. If obesity alone were an intractable cause of cesareans, the cesarean rates between these two studies should be similar, yet they were drastically different. This suggests that labor management influences cesarean rates, even in very obese women.

The sheer volume of cesareans being done in obese women and the fact that we experience more complications from cesareans means this is a critical public health issue. Sadly, few care providers and researchers are taking this issue seriously.

A high cesarean rate is not an inevitable outcome for obese women, and it is likely that with more careful management protocols, the cesarean rate in obese women can be lowered.

That is a message that needs to get out to women of size and the healthcare professionals who care for them. And that is why this is a frequent topic on my blog.

Summary

For those who read my blog and wonder why cesareans are such a frequent topic of conversation, the answer is because it needs to be.

Many doctors, researchers, and media articles have blamed the nation's rise in cesarean rate on the "obesity epidemic," as well as other factors like older mothers and bigger babies. Yet childbirth advocates Henci Goer and Amy Romano (CNM) question this rationale in their book, Optimal Care in Childbirth:

Cesarean rates do rise in correlation with factors such as maternal age and birth weight, which means that a proportional increase in the population would affect the cesarean rate, but this is not the end of the story. U.S. cesarean rates have increased sharply at every maternal age, in every ethnic group, and for every demographic or medical risk factor.   

The relationship between maternal weight and cesarean rate cannot be ascertained directly, but the proportion of high-weight women increased from 1991 to 1996 while cesarean rates were falling and held steady from 1999 to 2004 when cesarean rates were once again on the rise.

An increase in macrosomic babies also fails to explain the rise in cesarean rates. Cesarean rates have increased in all weight categories, the incidence of macrosomia declined from 1990 to 2000, and cesarean rates with macrosomia have soared: U.K. physicians delivered only 3% of babies weighing 4000 g or more via cesarean in 1958, while U.S. obstetricians today may perform cesareans on as many as half the women with babies of this size.

The rise in the cesarean rate in the U.S. and other countries is not just about maternal and fetal factors, but about the ways providers manage labors, their perception of risk, and their drastically lowered thresholds for surgical intervention. Care providers must stop blaming women alone for the rise in the cesarean rate and start acknowledging their own role in its rise.

Yes, I talk about cesareans a LOT, and I will continue to do so.  This is a critical issue on a public health basis, and particularly so for women of size. 

But don't take my word for it. Read the research.  

To help you understand the issue, here are some key research references that discuss the short- and long-term implications of a high cesarean rate, as well as research about the cesarean rate in high-BMI women. There are links to the abstracts of each article; just click on the PMID (Pub Med ID) number after each entry.  

Most care providers and researchers shrug off the extreme cesarean rates in women of size as a natural consequence of their obesity, and imply that this is simply the price they pay for daring to have a baby without losing weight.  

However, a few brave researchers and advocates are now starting to question whether cesarean rates need to be so high in obese women, and whether other factors like exaggerated perception of risk, overuse of labor interventions, and an inappropriately lowered surgical threshold also play a significant role.  

Bottom line, we need to be concerned about high cesarean rates for all women, and especially so for women of size.  


Research References

Long-Term Public Health Implications of a High Cesarean Rate

J Matern Fetal Neonatal Med. 2011 Nov;24(11):1341-6. doi: 10.3109/14767058.2011.553695. The effect of cesarean delivery rates on the future incidence of placenta previa, placenta accreta, and maternal mortality. Solheim KN, Esakoff TF, Little SE, Cheng YW, Sparks TN, Caughey AB.  PMID: 21381881 

OBJECTIVE: The overall annual incidence rate of caesarean delivery in the United Sates has been steadily rising since 1996, reaching 32.9% in 2009. Primary cesareans often lead to repeat cesareans, which may lead to placenta previa and placenta accreta. This study's goal was to forecast the effect of rising primary and secondary cesarean rates on annual incidence of placenta previa, placenta accreta, and maternal mortality. RESULTS: If primary and secondary cesarean rates continue to rise as they have in recent years, by 2020 the cesarean delivery rate will be 56.2%, and there will be an additional 6236 placenta previas, 4504 placenta accretas, and 130 maternal deaths annually. The rise in these complications will lag behind the rise in cesareans by approximately 6 years. CONCLUSIONS: If cesarean rates continue to increase, the annual incidence of placenta previa, placenta accreta, and maternal death will also rise substantially.

Semin Perinatol. 2012 Oct;36(5):315-23. doi: 10.1053/j.semperi.2012.04.013. Implications of the first cesarean: perinatal and future reproductive health and subsequent cesareans, placentation issues, uterine rupture risk, morbidity, and mortality. Silver RM. PMID: 23009962

Rates of cesarean delivery have substantially increased worldwide during the past 30 years. Indeed, almost one-third of deliveries in the United States are cesareans. Most cesareans are safe, and major complications are uncommon. However, there is a "concealed" downside to cesarean deliveries. There are rare but life-threatening morbidities that may occur, which are often overlooked because most cesareans go well. In addition, subsequent pregnancies are fraught with an increased risk of both maternal and fetal complications. The worst of these are associated with placental problems such as previa, abruption, and accreta. The risk dramatically worsens in patients with multiple repeat cesarean deliveries. This article will summarize and highlight the implications of the rising cesarean rate on maternal and fetal morbidity and mortality.

 Clin Perinatol. 2011 Jun;38(2):297-309. Delivery after prior cesarean: maternal morbidity and mortality. Cheng YW, Eden KB, Marshall N, Pereira L, Caughey AB, Guise JM.  PMID: 21645797

Nearly 1 in 3 pregnant women in the United States undergo cesarean. This trend is contrary to the national goal of decreasing cesarean delivery in low-risk women. The decline in vaginal birth after cesarean (VBAC) contributes to the continual increase in cesarean deliveries. Prior cesarean delivery is the most common indication for cesarean and accounts for more than one-third of all cesareans. The appropriate use and safety of cesarean and VBAC are of concern not only at the individual patient and clinician level but they also have far-reaching public health and policy implications at the national level.

Cesareans and Neonatal Mortality

Birth. 2008 Mar;35(1):3-8. Neonatal mortality for primary cesarean and vaginal births to low-risk women: application of an "intention-to-treat" model. MacDorman MF, Declercq E, Menacker F, Malloy MH.  PMID: 18307481

...METHODS: Low-risk births were singleton, term (37-41 weeks' gestation), vertex births, with no reported medical risk factors or placenta previa and with no prior cesarean section. All U.S. live births and infant deaths for the 1999 to 2002 birth cohorts (8,026,415 births and 17,412 infant deaths) were examined. Using the intention-to-treat methodology, a "planned vaginal delivery" category was formed by combining vaginal births and cesareans with labor complications or procedures since the original intention in both cases was presumably a vaginal delivery. This group was compared with cesareans with no labor complications or procedures, which is the closest approximation to a "planned cesarean delivery" category possible, given data limitations...RESULTS: The unadjusted neonatal mortality rate for cesarean deliveries with no labor complications or procedures was 2.4 times that for planned vaginal deliveries. In the most conservative model, the adjusted odds ratio for neonatal mortality was 1.69 (95% CI 1.35-2.11) for cesareans with no labor complications or procedures, compared with planned vaginal deliveries. CONCLUSIONS: The finding that cesarean deliveries with no labor complications or procedures remained at a 69 percent higher risk of neonatal mortality than planned vaginal deliveries is important, given the rapid increase in the number of primary cesarean deliveries without a reported medical indication.

J Obstet Gynaecol Res. 2012 Apr 9. doi: 10.1111/j.1447-0756.2011.01818.x. Risk of infant mortality with weekend versus weekday births: A population-based study. Salihu HM, Ibrahimou B, August EM, Dagne G.  PMID: 22487462

AIM: To examine the association between infant mortality, the day of birth and sociodemographic factors. Methods: This population-based retrospective study analyzed all singleton live births in the state of Missouri during the period 1989 to 1997. The main outcome of interest was infant survival after birth. Hazard ratios (HR) and 95% confidence intervals (CI) for the association between infant mortality and the day of birth were obtained through parametric time to event models. RESULTS: The neonatal mortality rate was higher on weekends (3.25/1000) compared to weekdays (2.87/1000) (P=0.042). Cesarean section delivery increased the risk of neonatal death by a magnitude of 31.5 compared to vaginal births (HR=31.47, 95% CI: 15.79, 62.74). Adolescent females (age <18) were more likely to experience neonatal (HR=2.20, 95% CI: 1.47, 3.31), post-neonatal (HR=2.20, 95% CI: 1.47, 3.30) and infant mortality (HR=4.06, CI: 2.02, 8.14). CONCLUSIONS: Cesarean section delivery heightens the risk of all infant death, including neonatal and post-neonatal death, regardless of the day of birth, underscoring the need for multi-tiered strategies to reduce the occurrence of medically unnecessary cesarean sections. Furthermore, the elevated risk of infant mortality among adolescent mothers highlights the importance of enhanced preconception care and age-appropriate pregnancy prevention interventions.

J Midwifery Womens Health. 2012 Jan;57(1):12-7. doi: 10.1111/j.1542-2011.2011.00142.x. First birth cesarean and risk of antepartum fetal death in a subsequent pregnancy. Osborne C, Ecker JL, Gauvreau K, Lieberman E.  PMID: 22251907

...METHODS: Data for this retrospective cohort study were taken from a database of all women who gave birth at Brigham and Women's Hospital during 4 waves of data collection beginning in 1994 and ending in 2002. We calculated the risk of antepartum fetal death in the subsequent pregnancy for women whose first birth was by cesarean compared to women with a vaginal first birth. Survival analysis was used to examine the influence of gestational age at birth. RESULTS: ...The risk of antepartum fetal death in the subsequent pregnancy for women whose first birth was by cesarean was significantly greater than the risk for women whose first birth was vaginal (odds ratio 2.6; 95% confidence interval, 1.1-6.2)...DISCUSSION: In these data, first birth by cesarean was associated with an increased risk of antepartum fetal death in a subsequent pregnancy. Our findings suggest that antepartum fetal deaths in subsequent pregnancies might be prevented by avoiding primary cesarean birth. 

Cesareans and Neonatal Morbidity 

J Perinat Med. 2011 May;39(3):241-4. doi: 10.1515/JPM.2011.050. Effect of prior cesarean delivery on neonatal outcomes. Abenhaim HA, Benjamin A.  PMID: 21426242

METHODS:We conducted a retrospective cohort study on all women with a prior livebirth who delivered at the Royal Victoria Hospital between 2001 and 2006...to estimate the adjusted effect of a previous cesarean delivery on adverse neonatal outcomes. RESULTS: A total of 18,673 births took place of which 9708 were in women with a prior livebirth (77.0% with no previous cesarean delivery and 23.0% with a previous cesarean delivery). As compared to newborns delivered by mothers with no prior cesarean delivery, increasing number of prior cesarean deliveries was associated with an increasing risk of preterm birth [odds ratio (OR) 1.23, 95% confidence interval (CI) 1.09-1.39]; respiratory distress syndrome (OR 3.54, 95% CI 2.02-5.91); and admission to the neonatal intensive care unit (OR 1.41, 95% CI 1.25-1.60). These findings were predominantly due to differences in gestational age and mode of delivery. CONCLUSION: Having a prior cesarean delivery is associated with an increased risk of adverse neonatal outcomes. Adverse neonatal outcomes in subsequent pregnancies is additional evidence to suggest that unless specifically indicated, cesarean delivery should be avoided.

Cesareans and Maternal Mortality

Source

Obstet Gynecol. 2006 Sep;108(3 Pt 1):541-8. Postpartum maternal mortality and cesarean delivery. Deneux-Tharaux C, Carmona E, Bouvier-Colle MH, Bréart G.  PMID: 16946213

...RESULTS: After adjustment for potential confounders, the risk of postpartum death was 3.6 times higher after cesarean than after vaginal delivery (odds ratio 3.64 95% confidence interval 2.15-6.19). Both prepartum and intrapartum cesarean delivery were associated with a significantly increased risk. Cesarean delivery was associated with a significantly increased risk of maternal death from complications of anesthesia, puerperal infection, and venous thromboembolism. The risk of death from postpartum hemorrhage did not differ significantly between vaginal and cesarean deliveries. CONCLUSION: Cesarean delivery is associated with an increased risk of postpartum maternal death. Knowledge of the causes of death associated with this excess risk informs contemporary discussion about cesarean delivery on request and should inform preventive strategies.

Cesareans and Maternal Complications

Acta Obstet Gynecol Scand. 2009 Jul 29:1-8.   Risk of selected postpartum infections after cesarean section compared with vaginal birth: a five-year cohort study of 32,468 women. Leth RA, Møller JK, Thomsen RW, Uldbjerg N, Nørgaard M.  PMID: 19642043 

OBJECTIVES: To compare the risk of postpartum infections within 30 days after vaginal birth, emergency, or elective cesarean section (CS). DESIGN: Register-based cohort study in Denmark. PARTICIPANTS: A total of 32,468 women giving birth in hospitals in the County of Aarhus, Denmark, during the period 2001-2005. METHODS: Data from various hospital registries were combined and infections were identified by positive cultures, prescriptions for antibiotics and, re-operative procedures. Risk of postpartum infection was estimated and adjustment for potentially confounders was performed. RESULTS: Within 30 days postpartum, 7.6% of women who had underwent CS and 1.6% of women having a vaginal birth acquired an infection, yielding an adjusted odds ratio (OR) of 4.71, 95% confidence interval (CI): 4.08-5.43. The prevalence of postpartum urinary tract infection (UTI) was 2.8% after CS and 1.5% after vaginal birth corresponding to an adjusted OR = 1.68, 95% CI: 1.38-2.03. The risk of UTI did not differ between emergency and elective CS. The prevalence of WI [wound infection] was 5.0% after CS and 0.08% after vaginal birth. Moreover, we found a nearly 50% higher risk of postpartum WI after emergency CS compared to elective CS (OR = 1.49, 95% CI: 1.13-1.97). More than 75% (697/907) of postpartum infections appeared after hospital discharge. CONCLUSIONS: The risk of postpartum infection seems to be nearly five-fold increased after CS compared with vaginal birth. This may be of concern since the prevalence of CS is increasing.

J Matern Fetal Neonatal Med. 2011 Apr 4. Jan;25(1):74-7. doi: 10.3109/14767058.2011.565391 Obstetrical Hysterectomy, cesarean delivery and abnormal placentation. Dandolu V, Graul AB, Lyons A, Matteo D.  PMID: 21463209

...STUDY DESIGN: This was a retrospective study of all cases of Obstetrical Hysterectomy performed between January 1993 and December 2005 at Temple University Hospital, Philadelphia, Pennsylvania. RESULTS: During the study years, 19 patients underwent Obsterical Hysterectomy. Of these, 14 (73.7%) had cesarean during their current delivery. Further, 9 (47.4%) of the 19 had previous cesarean deliveries (CDs), with 5 (56%) of the 9 having had two or more previous CDs. Only two women (10.5%) never had cesarean either in the current or previous pregnancy. Eighteen of the women had singleton pregnancies, while only one woman had a twin gestation. A total of 42.1% of the cases had abnormal placentation with 21% experiencing placenta accreta, 15.8% with placenta previa, and 5.3% with placental abruption. A variety of complications arose including fever (52.6%) and blood transfusion (84.2%). CONCLUSION: CD in the current pregnancy and history of CD were strong risk factors for Obstetrical Hysterectomy. There was also a high occurrence of Obstetrical Hysterectomy in patients who had abnormal placentation. This information should be used to counsel women regarding the increased risk of remote complications of CD while discussing the route of delivery.

Acta Obstet Gynecol Scand. 2010 Jul;89(7):896-902. Cesarean delivery in Finland: maternal complications and obstetric risk factors. Pallasmaa N, Ekblad U, Aitokallio-Tallberg A, Uotila J, Raudaskoski T, Ulander VM, Hurme S.  PMID:  20583935

OBJECTIVE: To assess the rate of maternal complications related to cesarean section (CS) and to compare morbidity between elective, emergency and crash-emergency CS. To establish risk factors associated with maternal CS morbidity. DESIGN: A prospective multicenter cohort study. SETTING: Twelve delivery units in Finland. POPULATION: Women delivering by CS (n = 2,496) during a 6 months period in the study hospitals...RESULTS: About 27% of women delivering by CS had complications; 10% had severe complications. The complication rate was higher in emergency CS than in elective CS, and highest in crash-emergency CS. Significant independent risk factors for maternal morbidity were emergency CS and crash-emergency CS compared to elective CS (OR 1.8; 95% confidence interval (CI) 1.5-2.2), pre-eclampsia (OR 1.5; CI 1.1-2.0), maternal obesity (OR 1.4; CI 1.1-1.8) and maternal increasing age (OR 1.1; CI 1.03-1.2 per each 5 years). CONCLUSIONS: Maternal complications are frequent in CS, and although performing CS electively reduces the occurrence of complications, the frequency is still high. The complication rate depends on the degree of emergency, and increases with maternal obesity, older age and pre-eclampsia.

Am J Obstet Gynecol. 2009 Jul;201(1):56.e1-6. Adhesion development and morbidity after repeat cesarean delivery. Tulandi T, Agdi M, Zarei A, Miner L, Sikirica V.  PMID:  19576375

OBJECTIVE: The purpose of this study was to evaluate the development and implications of intraabdominal adhesions after repeat cesarean section delivery (CS). STUDY DESIGN: We reviewed the charts of 1283 women who underwent repeat CS and 203 other women who underwent primary CS. Primary outcome measures were incidence and extent of adhesions, incision-to-delivery interval, and operating time. RESULTS: No adhesions were found in primary CS. Compared with those women with a second CS (24.4%), significantly more women had adhesions after 3 CSs (42.8%; 95% confidence interval [CI], 0.84-0.99). Compared with a first CS (7.7 +/- 0.3 minutes), the delivery time was significantly longer at subsequent CSs (second CS, 9.4 +/- 0.1 minutes; 95% CI, 1-2; third CS, 10.6 +/- 0.3 minutes; 95% CI, 2-4; >or= 4 CSs, 10.4 +/- 0.1 minutes; 95% CI, 1-2). However, complication rates in those women with >or= 2 CSs were comparable with primary CS. CONCLUSION: Increased adhesion development and a longer time to delivery were found with each subsequent CS. 

Cesareans and Future Placental Complications

Obstet Gynecol. 2006 Apr;107(4):771-8. Previous cesarean delivery and risks of placenta previa and placental abruption. Getahun D, Oyelese Y, Salihu HM, Ananth CV. PMID: 16582111

OBJECTIVE: To examine the association between cesarean delivery and previa and abruption in subsequent pregnancies. METHODS: A retrospective cohort study of first 2 (n = 156,475) and first 3 (n = 31,102) consecutive singleton pregnancies using the 1989-1997 Missouri longitudinally linked data were performed...RESULTS: Rates of previa and abruption were 4.4 (n = 694) and 7.9 (n = 1,243) per 1,000 births, respectively. The pregnancy after a cesarean delivery was associated with increased risk of previa (0.63%) compared with a vaginal delivery (0.38%, RR 1.5, 95% confidence interval [CI] 1.3-1.8). Cesarean delivery in the first and second births conferred a two-fold increased risk of previa in the third pregnancy (RR 2.0, 95% CI 1.3-3.0) compared with first two vaginal deliveries. Women with a cesarean first birth were more likely to have an abruption in the second pregnancy (0.95%) compared with women who had a vaginal first birth (0.74%, RR 1.3, 95% CI 1.2-1.5). Two consecutive cesarean deliveries were associated with a 30% increased risk of abruption in the third pregnancy (RR 1.3, 95% CI 1.0-1.8). A second pregnancy within a year after a cesarean delivery was associated with increased risks of previa (RR 1.7, 95% CI 0.9-3.1) and abruption (RR 1.5, 95% CI 1.1-2.3). CONCLUSION: A cesarean first birth is associated with increased risks of previa and abruption in the second pregnancy. There is a dose-response pattern in the risk of previa, with increasing number of prior cesarean deliveries. A short interpregnancy interval is associated with increased risks of previa and abruption.

Risks of Planned Cesarean vs. Planned Vaginal Birth

CMAJ. 2007 Feb 13;176(4):455-60. Maternal mortality and severe morbidity associated with low-risk planned cesarean delivery versus planned vaginal delivery at term. Liu S, Liston RM, Joseph KS, Heaman M, Sauve R, Kramer MS; Maternal Health Study Group of the Canadian Perinatal Surveillance System.  PMID: 17296957

...METHODS: Using the Canadian Institute for Health Information's Discharge Abstract Database, we carried out a retrospective population-based cohort study of all women in Canada (excluding Quebec and Manitoba) who delivered from April 1991 through March 2005. Healthy women who underwent a primary cesarean delivery for breech presentation constituted a surrogate "planned cesarean group" considered to have undergone low-risk elective cesarean delivery, for comparison with an otherwise similar group of women who had planned to deliver vaginally. RESULTS: The planned cesarean group comprised 46,766 women v. 2,292,420 in the planned vaginal delivery group; overall rates of severe morbidity for the entire 14-year period were 27.3 and 9.0, respectively, per 1000 deliveries. The planned cesarean group had increased postpartum risks of cardiac arrest (adjusted odds ratio [OR] 5.1, 95% confidence interval [CI] 4.1-6.3), wound hematoma (OR 5.1, 95% CI 4.6-5.5), hysterectomy (OR 3.2, 95% CI 2.2-4.8), major puerperal infection (OR 3.0, 95% CI 2.7-3.4), anesthetic complications (OR 2.3, 95% CI 2.0-2.6), venous thromboembolism (OR 2.2, 95% CI 1.5-3.2) and hemorrhage requiring hysterectomy (OR 2.1, 95% CI 1.2-3.8), and stayed in hospital longer (adjusted mean difference 1.47 d, 95% CI 1.46-1.49 d) than those in the planned vaginal delivery group, but a lower risk of hemorrhage requiring blood transfusion (OR 0.4, 95% CI 0.2-0.8). Absolute risk increases in severe maternal morbidity rates were low (e.g., for postpartum cardiac arrest, the increase with planned cesarean delivery was 1.6 per 1000 deliveries, 95% CI 1.2-2.1). The difference in the rate of in-hospital maternal death between the 2 groups was nonsignificant (p = 0.87). INTERPRETATION: Although the absolute difference is small, the risks of severe maternal morbidity associated with planned cesarean delivery are higher than those associated with planned vaginal delivery. These risks should be considered by women contemplating an elective cesarean delivery and by their physicians.

Cesareans and Long-Term Infant Outcomes 

Clin Perinatol. 2011 Jun;38(2):321-31. Cesarean Versus Vaginal Delivery: Long-term Infant Outcomes and the Hygiene Hypothesis. Neu J, Rushing J.  PMID:  21645799

Concurrent with the trend of increasing cesarean delivery numbers, there has been an epidemic of both autoimmune diseases and allergic diseases. Several theories have emerged suggesting that environmental influences are contributing to this phenomenon, most notably, the hygiene hypothesis. This article provides background about the human microbiota and its relationship to the developing immune system as well as the relationship of mode of delivery on the colonization of the infant intestine, development of the immune system, and subsequent childhood allergies, asthma, and autoimmune diseases.

Gut Microbes. 2011 Mar 1;2(2). [Epub ahead of print] Cesarean delivery is associated with celiac disease but not inflammatory bowel disease in children. Decker E, Hornef M, Stockinger S.  PMID:  21637025

The postnatal period represents a particularly dynamic phase in the establishment of the host-microbial homeostasis. The sterile protected intestinal mucosa of the fetus becomes exposed to and subsequently colonized by a complex and diverse bacterial community. Both, the exposure to microbial ligands and the bacterial colonization have been described to differ between neonates born vaginally or by cesarean delivery. These differences might influence the development of the mucosal immune system, the establishment of a stable intestinal host-microbial homeostasis, and ultimately contribute to the risk to acquire immune mediated diseases later in life. Indeed, an increased risk for atopic diseases such as allergic rhinitis and asthma was reported in children born by cesarean delivery. Our recent study described an association between cesarean delivery and celiac disease. Here we summarize the available information on postnatal microbial colonization and the influence of the mode of delivery on flora composition and host microbial homeostasis. We discuss possible consequences of the mode of delivery on epithelial barrier function and the establishment of the mucosal immune system and speculate on functional links between flora alterations and the development of inappropriate host immune responses that may contribute to enteric inflammatory diseases.

Maternal Obesity and High Cesarean Rates

Am J Obstet Gynecol. 2004 Apr;190(4):1091-7. Obesity, obstetric complications and cesarean delivery rate--a population-based screening study. Weiss JL, Malone FD, Emig D, Ball RH, Nyberg DA, Comstock CH, Saade G, Eddleman K, Carter SM, Craigo SD, Carr SR, D'Alton ME; FASTER Research Consortium. PMID: 15118648

Source

OBJECTIVE: This study was undertaken to determine whether obesity is associated with obstetric complications and cesarean delivery. METHODS: A large prospective multicenter database was studied. Subjects were divided into 3 groups: body mass index (BMI) less than 30 (control), 30 to 34.9 (obese), and 35 or greater (morbidly obese). Groups were compared by using univariate and multivariable logistic regression analyses. RESULTS: The study included 16,102 patients: 3,752 control, 1,473 obese, and 877 morbidly obese patients. Obesity and morbid obesity had a statistically significant association with gestational hypertension (odds ratios [ORs] 2.5 and 3.2), preeclampsia (ORs 1.6 and 3.3), gestational diabetes (ORs 2.6 and 4.0), and fetal birth weight greater than 4000 g (ORs 1.7 and 1.9) and greater than 4500 g (ORs 2.0 and 2.4). For nulliparous patients, the cesarean delivery rate was 20.7% for the control group, 33.8% for obese, and 47.4% for morbidly obese patients. CONCLUSION: Obesity is an independent risk factor for adverse obstetric outcome and is significantly associated with an increased cesarean delivery rate.

Am J Obstet Gynecol. 1997 Aug;177(2):333-7; discussion 337-41. The Preterm Prediction Study: association of cesarean delivery with increases in maternal weight and body mass index. Brost BC, Goldenberg RL, Mercer BM, Iams JD, Meis PJ, Moawad AH, Newman RB, Miodovnik M, Caritis SN, Thurnau GR, Bottoms SF, Das A, McNellis D. PMID: 9290448

[Kmom note: In a sub-analysis, this study found a more than 70% cesarean rate in women with a BMI over 52.]

...STUDY DESIGN: Maternal weight and height were prospectively collected on 2929 women in the National Institutes of Health Maternal-Fetal Medicine Units Network Preterm Prediction Study. Prepregnancy and 27- to 31-week maternal weight and height were used to calculate the body mass index, and its contribution to the risk of cesarean delivery was determined. Women with prenatally diagnosed congenital anomalies (n = 89) and pregestational diabetes (n = 31) were excluded from analysis. RESULTS: Univariate analysis of risk factors for cesarean delivery in the 2809 eligible women revealed a decreased risk of cesarean delivery with maternal age < 18 years and multiparity  increased risk of cesarean delivery was noted with maternal age > 35 years and a male fetus. Increases in either prepregnancy or 27- to 31-week maternal weight (5-pound units) or body mass index (1.0 kg/m2 units) were significantly associated with an increased odds of cesarean delivery (p = 0.0001). Each unit increase in prepregnancy or 27- to 31-week body mass index resulted in a parallel increase in the odds of cesarean delivery of 7.0% and 7.8%, respectively. Multivariable stepwise logistic regression analysis confirmed the association of male fetus, age, nulliparity, and body mass index as significant variables contributing to cesarean delivery risk. CONCLUSIONS: The risk of cesarean delivery is associated with incremental changes in maternal weight and body mass index before and during pregnancy after adjustment for potential confounding factors. Prepregnancy counseling about optimizing maternal weight and monitoring weight gain during pregnancy to decrease the risk of cesarean delivery are supported by this study.

Am J Obstet Gynecol. 2010 Sep;203(3):264.e1-7. doi: 10.1016/j.ajog.2010.06.024. Epub 2010 Jul 31. The maternal body mass index: a strong association with delivery route. Kominiarek MA, Vanveldhuisen P, Hibbard J, Landy H, Haberman S, Learman L, Wilkins I, Bailit J, Branch W, Burkman R, Gonzalez-Quintero VH, Gregory K,Hatjis C, Hoffman M, Ramirez M, Reddy UM, Troendle J, Zhang J; Consortium on Safe Labor. PMID: 20673867

OBJECTIVE: We sought to assess body mass index (BMI) effect on cesarean risk during labor. STUDY DESIGN: The Consortium on Safe Labor collected electronic data from 228,668 deliveries. Women with singletons > or = 37 weeks and known BMI at labor admission were analyzed in this cohort study. Regression analysis generated relative risks for cesarean stratifying for parity and prior cesarean while controlling for covariates. RESULTS: Of the 124,389 women, 14.0% had cesareans. Cesareans increased with increasing BMI for nulliparas and multiparas with and without a prior cesarean. Repeat cesareans were performed in > 50% of laboring women with a BMI > 40 kg/m(2). The risk for cesarean increased as BMI increased for all subgroups, P < .001. The risk for cesarean increased by 5%, 2%, and 5% for nulliparas and multiparas with and without a prior cesarean, respectively, for each 1-kg/m(2) increase in BMI. CONCLUSION: Admission BMI is significantly associated with delivery route in term laboring women. Parity and prior cesarean are other important predictors.

Am J Obstet Gynecol. 2012 May;206(5):417.e1-6. doi: 10.1016/j.ajog.2012.02.037. Epub 2012 Mar 7. Maternal superobesity and perinatal outcomes. Marshall NE1, Guild C, Cheng YW, Caughey AB, Halloran DR. PMID: 22542116

OBJECTIVE: The purpose of this study was to determine the effect of maternal super obesity (body mass index [BMI], ≥ 50 kg/m(2)) compared with morbid obesity (BMI, 40-49.9 kg/m(2)) or obesity (BMI, 30-39.9 kg/m(2)) on perinatal outcomes. STUDY DESIGN: We conducted a retrospective cohort study of birth records that were linked to hospital discharge data for all liveborn singleton term infants who were born to obese Missouri residents from 2000-2006. We excluded major congenital anomalies and women with diabetes mellitus or chronic hypertension. RESULTS: There were 64,272 births that met the study criteria, which included 1185 superobese mothers (1.8%). Superobese women were significantly more likely than obese women to have preeclampsia (adjusted relative risk [aRR], 1.7; 95% confidence interval [CI], 1.4-2.1), macrosomia (aRR, 1.8; 95% CI, 1.3-2.5), and cesarean delivery (aRR, 1.8; 95% CI, 1.5-2.1). Almost one-half of all superobese women (49.1%) delivered by cesarean section, and 33.8% of superobese nulliparous women underwent scheduled primary cesarean delivery. CONCLUSION: Women with a BMI of ≥ 50 kg/m(2) are at significantly increased risk for perinatal complications compared with obese women with a lower BMI.

Obstet Gynecol. 2014 May;123 Suppl 1:159S-60S. doi: 10.1097/01.AOG.0000447159.35865.07. Perinatal outcomes in the super obese: a community hospital experience. Papp MM1, Lindsay A, Mariona F, Chatterjee S. PMID: 24770057

[Kmom note: The cesarean rate was a sky-high 80% in women with a BMI over 50.]

...Ongoing observational study involving pregnant women with body mass index equal or above 50 kg/m. The study was approved by the Wayne State University institutional review board. The patients were identified in the outpatient clinic and private practice offices and followed during their prenatal care and delivery. RESULTS: One hundred thirteen women are included. Body mass index was between 50 and 106 kg/m. Delivery occurred between 26 and 40 weeks of gestation. A total of 44.24% were delivered by primary cesarean delivery, 36% by repeat cesarean delivery, and 19% by vaginal delivery...Unsuccessful spontaneous or induced labor and trial of labor after a previous cesarean delivery was increased in this population. Wound infection occurred in 17%...

Questioning High Cesarean Rates in Obese Women

J Matern Fetal Neonatal Med. 2012 Nov 28. [Epub ahead of print] Cesarean delivery in obese women: a comprehensive review. Wispelwey BP, Sheiner E.  PMID: 23130683

BACKGROUND: Obesity (BMI ≥30) is a significant independent risk factor for many gestational complications, including cesarean delivery (CD). While CD rates are increasing in women of every BMI, the trend is more pronounced as maternal weight increases. OBJECTIVE: This review seeks to describe the risk modulators that explain the high prevalence of CD in obese women, as well as to discuss the excess complications of the procedure in this group of parturients. In assessing the rationale for the procedure and weighing this against the excess risks involved, a clearer indication of when to perform CD in obese women might be developed. RESULTS: A thorough review of the literature indicates that a decreased cervical dilation rate, an increased induction rate, the presence of comorbid conditions, concern about shoulder dystocia, and weight gain in excess of recommendations during pregnancy all may contribute to the high rate of CD in obese women. Obese women are at increased risk of CD-related complications including anesthetic complications, wound complications, venous thromboembolism (VTE), and failure of vaginal birth after CD. CONCLUSIONS: Given the excess risks associated with CD in obese women, and that some of the rationale for the procedure (e.g. slower labor, concern about shoulder dystocia) may not be justified based on current evidence, a reassessment of the threshold at which obese women are recommended for CD is necessary.

Am J Obstet Gynecol. 1978 Jul 1;131(5):479-83. Pregnancy in the massively obese: course, outcome, and obesity prognosis of the infant. Edwards LE, Dickes WF, Alton IR, Hakanson EY. PMID: 677188

The obstetric performance and pregnancy outcome in 208 massively obese patients who were delivered over an eight-year period were compared with those of nonobese control subjects. The incidence of obesity in their infants was also compared. No significant increase in the incidence of urinary tract infection, diabetes, breech presentation, cesarean section, forceps delivery, or maternal and infant morbidity was noted in the obese women. Significantly increased incidences of hypertensive disorders of pregnancy (p less than 0.01), gestational diabetes (p less than 0.01), inadequate weight gain (p less than 0.001), and wound or episiotomy infection (p less than 0.05) were observed in the study group. The mean birth weight of the infants of obese women was 209 grams greater than that of the control subjects. A significantly increased number of the obese patients were delivered of excessive-sized infants. Despite this, the incidence of obesity in infants of obese women was not significantly increased at birth or six months of age. By 12 months of age, however, these infants were significantly more obese than the control infants.

Am J Obstet Gynecol. 2014 Jun 20. pii: S0002-9378(14)00625-5. doi: 10.1016/j.ajog.2014.06.045. [Epub ahead of print] Mode of Delivery in Women with Class III Obesity: Planned Cesarean compared to Induction of Labor. Subramaniam A1, Jauk VC2, Goss AR3, Alvarez MD3, Reese CS4, Edwards RK2. PMID: 24956550

OBJECTIVE: To compare maternal and neonatal outcomes between planned cesarean delivery and induction of labor in women with class III obesity (body mass index [BMI] ≥40 kg/m2). STUDY DESIGN: In this retrospective cohort study, we identified all women with a BMI ≥40 kg/m2 who delivered a singleton at our institution from January 2007 to February 2013 via planned cesarean or induction of labor (regardless of eventual delivery route) at 37-41 weeks. Patients in spontaneous labor were excluded. The primary outcome was a composite of maternal morbidity including death as well as operative, infection, and thromboembolic complications. The secondary outcome was a neonatal morbidity composite. Additional outcomes included individual components of the composites. Student's t, chi-square, and Fisher's exact tests were used for statistical analysis. To calculate adjusted odds ratios (aOR), covariates were analyzed via multivariable logistic regression. RESULTS: 661 mother-infant pairs met enrollment criteria-399 inductions and 262 cesareans. Groups were similar in terms of pre-pregnancy weight, pregnancy weight gain, and delivery BMI. Of the 399 inductions, 258 had cervical ripening (64.7%) and 163 (40.9%) had a cesarean delivery. After multivariable adjustments, there was no significant difference in the maternal morbidity composite (aOR 0.98, 95% CI 0.55-1.77) or in the neonatal morbidity composite (aOR 0.81, 95% CI 0.37-1.77) between the induction and cesarean groups. CONCLUSIONS: In term pregnant women with class III obesity, planned cesarean does not appear to reduce maternal and neonatal morbidity compared to induction of labor.

Am J Perinatol. 2011 Oct;28(9):729-34. doi: 10.1055/s-0031-1280852. Extreme Morbid Obesity and Labor Outcome in Nulliparous Women at Term. Garabedian MJ, Williams CM, Pearce CF, Lain KY, Hansen WF. PMID: 21660900

We examined the prevalence of cesarean delivery (CD) among women with morbid obesity and extreme morbid obesity. Using Kentucky birth certificate data, a cross-sectional analysis of nulliparous singleton gestations at term was performed. We examined the prevalence of CD by body mass index (BMI; in kg/m (2)) using the National Institutes of Health/World Health Organization schema and a modified schema that separates extreme morbid obesity (BMI ≥50) from morbid obesity (BMI ≥40 to less than 50). Bivariate and multivariate analyses were performed. Multivariate modeling controlled for maternal age, estimated gestational age, birth weight, diabetes, and hypertensive disorders. Overall, 83,278 deliveries were analyzed. CD was most common among women with a prepregnancy BMI ≥50 (56.1%, 95% confidence interval 50.9 to 61.4%). Extreme morbid obesity was most strongly associated with CD (adjusted odds ratio 4.99, 95% confidence interval 4.00 to 6.22). Labor augmentation decreased the likelihood of CD among women with extreme morbid obesity, but this failed to reach statistical significance. We speculate a qualitative or quantitative deficiency in the hormonal regulation of labor exists in the morbidly obese parturient. More research is needed to better understand the influence of morbid obesity on labor.

BJOG. 2011 Mar;118(4):480-7. Planned vaginal delivery or planned caesarean delivery in women with extreme obesity. Homer CS, Kurinczuk JJ, Spark P, Brocklehurst P, Knight M. PMID: 21244616

[Kmom note: This study found a 30% cesarean and 70% vaginal birth rate for women with a BMI of 50 and over who labored.  Compare that to the 56% cesarean rate in a similar group of women in the Garabedian study above. Cesarean rates in very obese women are NOT just about their obesity but also about how their labors are managed.]  

OBJECTIVE: To compare the outcomes of planned vaginal versus planned caesarean delivery in a cohort of extremely obese women (body mass index ≥ 50 kg/m(2)).  DESIGN: A national cohort study using the UK Obstetric Surveillance System (UKOSS).  SETTING: All hospitals with consultant-led maternity units in the UK.  POPULATION: Five hundred and ninety-one extremely obese women delivering in the UK between September 2007 and August 2008.  METHODS: Prospective cohort identification through UKOSS routine monthly mailings.  MAIN OUTCOME MEASURES: Anaesthetic, postnatal and neonatal complication rates.  RESULTS: After adjustment, there were no significant differences in anaesthetic, postnatal or neonatal complications between women with planned vaginal delivery and planned caesarean delivery, with the exception of shoulder dystocia (3% versus 0%, P = 0.019). There were no significant differences in any outcomes in the subgroup of women who had no identified medical or antenatal complications.  CONCLUSIONS: This study does not provide evidence to support a routine policy of caesarean delivery for extremely obese women on the basis of concern about higher rates of delivery complications, but does support a policy of individualised decision-making on the mode of delivery based on a thorough assessment of potential risk factors for poor delivery outcomes.

Maternal Obesity, Induction of Labor, and Cesarean Rates

J Obstet Gynaecol Can. 2011 May;33(5):443-8. Higher caesarean section rates in women with higher body mass index: are we managing labour differently? Abenhaim HA, Benjamin A. PMID: 21639963

BACKGROUND: Higher body mass index has been associated with an increased risk of Caesarean section. The effect of differences in labour management on this association has not yet been evaluated. Methods: We conducted a cohort study using data from the McGill Obstetrics and Neonatal Database for deliveries taking place during a 10-year period. Women's BMI at delivery was categorized as normal (20 to 24.9), overweight (25 to 29.9), obese (30 to 39.9), or morbidly obese (≥ 40). We evaluated the effect of the management of labour on the need for Caesarean section using unconditional logistic regression models. RESULTS: Data were available for 11 922 women, of whom 2289 women had normal weight, 5663 were overweight, 3730 were obese, and 240 were morbidly obese. After adjustment for known confounding variables, increased BMI category was associated with an overall increase in the use of oxytocin and in the use of epidural analgesia, and with a decrease in use of forceps and vacuum extraction among second stage deliveries.  Higher BMI was also found to be associated with earlier decisions to perform a Caesarean section in the second stage of labour.  When adjusted for these differences in the management of labour, the increasing rate of Caesarean section observed with increasing BMI category was markedly attenuated (P less than 0.001).  CONCLUSION: Women with an increased BMI are managed differently in labour than women of normal weight. This difference in management in part explains the increased rate of Caesarean section observed with higher BMI.

Aust N Z J Obstet Gynaecol. 2011 Apr;51(2):172-4. Impact of morbid obesity on the mode of delivery and obstetric outcome in nulliparous singleton pregnancy and the implications for rural maternity services. Green C, Shaker D. PMID: 21466521

Obesity represents a rapidly emerging epidemic amongst pregnant women. Our study looks at the impact of morbid obesity on pregnant singleton nulliparous women in comparison with normal body mass index women. We conclude that morbid obesity is associated with a significantly higher risk of pre-existing medical conditions, developing antenatal complications, induction of labour, caesarean section and greater birth weight. However, there was no significant difference in caesarean section rates when adjusted for induction of labour. We also found no significant difference in length of hospital stay, postnatal complications and neonatal morbidity.

BJOG. 2005 Jun;112(6):768-72. Outcome of pregnancy in a woman with an increased body mass index. Usha Kiran TS, Hemmadi S, Bethel J, Evans J. PMID: 15924535

Source

...DESIGN: A population-based observational study. SETTING: University Hospital of Wales. The study sample was drawn from the Cardiff Births Survey, a population-based database comprising of a total of 60,167 deliveries in the South Glamorgan area between 1990 and 1999. POPULATION: Primigravid women with a singleton uncomplicated pregnancy with cephalic presentation of 37 or more weeks of gestation with accurate information regarding height and weight recorded at the booking visit (measured by the midwives) were included in the study. METHODS: Comparisons were made between women with a body mass index of 20-30 and those with more than 30. SPSS version 10 was used for statistical analysis. Student's t test, chi(2) and Fisher's exact tests were used wherever appropriate. MAIN OUTCOME MEASURES: Labour outcomes assessed were risk of postdates, induction of labour, mode of delivery, failed instrumental delivery, macrosomia and shoulder dystocia. Maternal adverse outcomes assessed were postpartum haemorrhage, blood transfusion, uterine and wound infection, urinary tract infection, evacuation of uterus, thromboembolism and third- or fourth-degree perineal tears. Fetal wellbeing was assessed using Apgar <7 at 5 minutes, trauma and asphyxia, cord pH < 7.2, babies requiring neonatal ward admissions, tube feeding and incubator. RESULTS: We report an increased risk [quoted as odds ratio (OR) and confidence intervals CI)] of postdates, 1.4 (1.2-1.7); induction of labour, 1.6 (1.3-1.9); caesarean section, 1.6 (1.4-2); macrosomia, 2.1 (1.6-2.6); shoulder dystocia, 2.9 (1.4-5.8); failed instrumental delivery, 1.75 (1.1-2.9); increased maternal complications such as blood loss of more than 500 mL, 1.5 (1.2-1.8); urinary tract infections, 1.9 (1.1-3.4); and increased neonatal admissions with complications such as neonatal trauma, feeding difficulties and incubator requirement. CONCLUSION: Obese women appear to be at risk of intrapartum and postpartum complications. Induction of labour appears to be the starting point in the cascade of events. They should be considered as high risk and counselled accordingly.

Am J Obstet Gynecol. 2014 Jul;211(1):53.e1-5. doi: 10.1016/j.ajog.2014.01.034. Epub 2014 Jan 31. Risk of cesarean in obese nulliparous women with unfavorable cervix: elective induction vs expectant management at term. Wolfe H1, Timofeev J2, Tefera E3, Desale S3, Driggers RW2. PMID: 24486226

OBJECTIVE: The objective of the study was to examine maternal and neonatal outcomes in obese nulliparous women with an unfavorable cervix undergoing elective induction of labor compared with expectant management after 39.0 weeks. STUDY DESIGN: This was a retrospective analysis of a cohort of nulliparous women with a vertex singleton gestation who delivered at MedStar Washington Hospital Center from 2007 to 2012. Patients with unfavorable cervix between 38.0 and 38.9 weeks (modified Bishop <5) and a body mass index of 30.0 kg/m(2) or greater at the time of delivery were included. Women undergoing elective induction between 39.0 and 40.9 weeks' gestation were compared with those who were expectantly managed beyond 39.0 weeks...RESULTS: Sixty patients meeting inclusion criteria underwent elective induction of labor and were compared with 410 patients expectantly managed beyond 39.0 weeks. The rate of cesarean delivery was significantly higher in the electively induced group (40.0% vs 25.9%, respectively, P = .022). Other maternal outcomes, including operative vaginal delivery, rate of third- or fourth-degree lacerations, chorioamnionitis, postpartum hemorrhage, and a need for a blood transfusion were similar. The neonatal intensive care unit admission rate was higher in the electively induced group (18.3% vs 6.3%, P = .001). Birthweight, umbilical artery pH less than 7.0, and Apgar less than 7 at 5 minutes were similar. CONCLUSION: Elective labor induction at term in obese nulliparous parturients carries an increased risk of cesarean delivery and higher neonatal intensive care unit admission rate as compared with expectant management.

Acta Obstet Gynecol Scand. 2013 Dec;92(12):1414-8. doi: 10.1111/aogs.12263. Maternal obesity and induction of labor. O'Dwyer V1, O'Kelly S, Monaghan B, Rowan A, Farah N, Turner MJ. PMID: 24116732

...Of 2000 women enrolled, 50.4% (n = 1008) were primigravidas and 17.3% (n = 346) were obese. The induction rate was 25.6% and the overall cesarean section rate 22.0%. Primigravidas were more likely to have labor induced than multigravidas (38.1% vs. 23.4%, p < 0.001). Compared with women with a normal BMI, obese primigravidas but not obese multigravidas were more likely to have labor induced. In primigravidas who had labor induced, the cesarean section rate was 20.6% (91/442) compared with 8.3% (17/206) in multigravidas who had labor induced (p < 0.001). In obese primigravidas, induction of labor was also more likely to be associated with other interventions such as epidural analgesia, fetal blood sampling and emergency cesarean section. In contrast, induction of labor in obese multigravidas was not only less common but also not associated with an increase in other interventions compared with multigravidas with a normal BMI. CONCLUSIONS: Due to the short-term and long-term implications of an unsuccessful induction in an obese primigravida, we recommend that induction of labor should only be undertaken for strict obstetric indications after careful consideration by an experienced clinician.

Risks of Cesareans in Obese Women

Am J Obstet Gynecol. 2010 Sep;203(3):276.e1-5. Epub 2010 Jul 31. Anesthesia complications during scheduled cesarean delivery for morbidly obese women. Vricella LK, Louis JM, Mercer BM, Bolden N.  PMID: 20678746

OBJECTIVE: We sought to estimate the morbidity associated with regional anesthesia in morbidly obese women undergoing scheduled cesarean delivery. STUDY DESIGN: This was a retrospective cohort study of women undergoing elective scheduled cesarean delivery from September 2004 through December 2008. RESULTS: A total of 142 morbidly obese, 251 overweight and obese, and 185 normal-weight women met inclusion criteria. Differences between groups were identified regarding: complicated placement (5.6%, 2.8%, and 0%, respectively; P = .007), failure to establish (2%, 0%, and 0%, respectively; P = .047), and insufficient duration (4%, 0%, and 0%, respectively; P = .02) of regional anesthesia.  The groups differed in the frequency of general anesthesia (6%, 0%, and 0%, respectively; P = .003), intraoperative hypotension (3%, 0%, and 0%, respectively; P = .01), and overall anesthetic complications (8.4%, 0%, and 0%, respectively; P less than .0001). Prepregnancy body mass index greater than or = 40 kg/m(2) (receiver operating characteristic area under the curve, 0.856; positive likelihood ratio, 4.0) and delivery body mass index greater than or = 45 kg/m(2) (receiver operating characteristic area under the curve, 0.877; positive likelihood ratio, 4.1) were predictive of anesthetic complications. CONCLUSION: Morbidly obese women have significant risk for anesthesia complications during cesarean delivery.

Am J Obstet Gynecol. 2010 Jul 31.  Complications of cesarean delivery in the massively obese parturient. Alanis MC, Villers MS, Law TL, Steadman EM, Robinson CJ.  PMID: 20678746

OBJECTIVE: The objective of the study was to determine predictors of cesarean delivery morbidity associated with massive obesity. STUDY DESIGN: This was an institutional review board-approved retrospective study of massively obese women (body mass index, greater than/=50 kg/m(2)) undergoing cesarean delivery. Bivariable and multivariable analyses were used to assess the strength of association between wound complication and various predictors. RESULTS: Fifty-eight of 194 patients (30%) had a wound complication. Most (90%) were wound disruptions, and 86% were diagnosed after hospital discharge (median postoperative day, 8.5; interquartile range, 6-12). Subcutaneous drains and smoking, but not labor or ruptured membranes, were independently associated with wound complication after controlling for various confounders. Vertical abdominal incisions were associated with increased operative time, blood loss, and vertical hysterotomy. CONCLUSION: Women with a BMI 50 kg/m(2) or greater have a much greater risk for cesarean wound complications than previously reported. Avoidance of subcutaneous drains and increased use of transverse abdominal wall incisions should be considered in massively obese parturients to reduce operative morbidity.

Obstet Gynecol. 2014 Aug;124(2 Pt 1):227-32. doi: 10.1097/AOG.0000000000000384. Extreme obesity and postcesarean maternal complications. Stamilio DM1, Scifres CM. PMID: 25004353

OBJECTIVE: To estimate the association of obesity and extreme obesity with maternal complications after cesarean delivery. METHODS: This was a secondary cohort analysis of a randomized controlled trial...For this secondary analysis, the exposure was obesity, stratified as normal or overweight (body mass index [BMI] less than 30), obese (BMI 30-45), or extremely obese (BMI higher than 45). The primary outcome was a composite of wound infection and endometritis. Secondary outcomes included wound infection, endometritis, wound opening, hematoma or seroma, and emergency department visit. We performed unadjusted and multivariable logistic regression analyses. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) are reported. RESULTS: We included 585 women in the analysis. Eighty-five patients (14.5%) had BMIs higher than 45. Rates of black race, chronic hypertension, diabetes, and gestational diabetes increased and operative duration increased with increasing obesity severity. Obese patients were more likely to have a cesarean delivery after labor and have a vertical skin incision or classical uterine incision. After controlling for confounders, extremely obese patients had a twofold to fourfold increase in postoperative complications, including the primary infectious outcome (18.8%, adjusted OR 2.7, CI 1.2-6.1), wound infection (18.8%, adjusted OR 3.4, CI 1.4-8.0), and emergency department visit (23.1%, adjusted OR 2.2, CI 1.03-4.9). CONCLUSION: Maternal extreme obesity is associated with a considerable increase in postcesarean wound complications.

J Matern Fetal Neonatal Med. 2014 Jul 24:1-5. [Epub ahead of print] The effect of maternal obesity on outcomes in patients undergoing tertiary or higher cesarean delivery. Mourad M1, Silverstein M, Bender S, Melka S, Klauser CK, Gupta S, Saltzman DH, Rebarber A, Fox NS. PMID: 25058127

...Retrospective cohort of patients cared for by a single MFM practice undergoing a tertiary or higher cesarean delivery from 2005 to 2013. Patients attempting vaginal delivery and patients with placenta accreta and/or placenta previa were excluded. We estimated the association of maternal obesity (prepregnancy BMI ≥ 30 kg/m2) and maternal outcomes. The primary outcome was a composite of severe maternal morbidity (uterine rupture, hysterectomy, blood transfusion, cystotomy requiring repair, bowel injury requiring repair, intensive care unit admission, thrombosis, re-operation, or maternal death). RESULTS: Three hundred and forty four patients met inclusion criteria, 73 (21.2%) of whom were obese. The composite outcome was significantly higher in the obese group (6.8% versus 1.8%, p = 0.024, aOR 4.36, 95% CI 1.21, 15.75). The incidence of several individual adverse outcomes were also increased in obese women, including blood transfusion (4.1% versus 0.7%, p = 0.033, aOR 7.36, 95% CI 1.19, 45.34), wound separation or infection (20.5% versus 5.9%, p < 0.001, aOR 4.05, 95% CI 1.75, 9.36) and 1-min Apgar score less than 7 (6.8% versus 1.9%, p = 0.024, aOR 4.40, 95% CI 1.21, 15.94). CONCLUSIONS: In patients undergoing a tertiary or higher cesarean delivery without placenta previa or accreta,obesity increases the risk of adverse outcomes. Obese patients are at risk for blood transfusion, low 1-min Apgar scores and postoperative wound complications.

Acta Obstet Gynecol Scand. 2010 May;89(5):658-63. doi: 10.3109/00016341003605727. Risks for peroperative excessive blood loss in cesarean delivery. Kolås T, Øian P, Skjeldestad FE.  PMID: 20218934

OBJECTIVE: To analyze risk factors for peroperative excessive blood loss at cesarean delivery. DESIGN: Case-control study. SETTING: Twenty-four of 26 maternity units in Norway with at least 500 expected deliveries per year. SAMPLE: A total of 2,778 women having singleton deliveries and participating in the Norwegian Breakthrough Project on Cesarean Section. METHODS: Elective and emergency operations were analyzed separately with extensive blood loss defined as hemorrhage > 1000 ml with controls defined as bleeding < 500 ml. All analyzes were done in SPSS (version 16.0) with chi-squared tests and logistic regression. MAIN OUTCOME MEASURES: Adjusted odds ratios (aOR) of extensive peroperative bleeding. RESULTS: The prevalence of excessive blood loss differed between women undergoing elective (2.1%) and emergency cesarean deliveries (3.3%). Among maternal factors, chronic maternal diseases, pregnancy and delivery related conditions, placenta previa (aOR 19.7; 95% CI 5.4-72.2) and transverse lie (aOR 4.9; 95% CI 0.9-26.5) were the only risk factors for extensive blood loss in elective operations, whereas placenta previa (aOR 8.4; 95% CI 2.4-29.9), placental abruption (aOR 2.0; 95% CI 2.0-14.5), intervention at full cervical dilation (aOR 3.2; 95% CI 1.4-7.1) and high BMI (aOR 3.4; 95% CI 1.6-7.2) were risks in emergency operations. CONCLUSION: The different risk pattern for excessive bleeding in cesarean deliveries should be recognized when planning available obstetric competence for surgery.

Articles about Practice Variation in Cesarean Rates

• http://californiawatch.org/health-and-welfare/profit-hospitals-performing-more-c-sections-4069 - article about the differences in cesarean rates between California hospitals
• http://www.boston.com/news/health/blog/2010/06/c_section_rates.html - article about the variation in cesarean rates among Boston-area hospitals
• http://www.bleedingheartland.com/diary/4976/iowa-csection-rates-vary-widely-by-hospital - article about the variation in cesarean rates in Iowa
• http://www.cleveland.com/healthfit/index.ssf/2010/01/post_26.html - article about the variation in cesarean rates in Ohio; graphics link here
• http://www.cesareanrates.com/blog/2012/8/22/practice-variation-in-new-jersey-27-miles-and-28-percentage.html - comparison of cesarean rates in 2 hospitals in NJ less than 30 miles apart
• http://www.childbirthconnection.org/article.asp?ck=10456 - article from Childbirth Connection about the possible reasons driving the increase in cesarean rate
• http://www.time.com/time/health/article/0,8599,2007754,00.html - article tying the rise in cesarean rates to the rise in induction rates
• http://www.icanofnj.com/csectionratebynicu.htm - do some hospitals have high cesarean rates only because they handle higher-risk patients?  CS rates by NICU levels in NJ
• http://www.webmd.com/baby/news/20110415/high-c-section-rates-arent-linked-to-healthier-babies - higher CS rates don't always result in healthier babies
• http://paa2005.princeton.edu/download.aspx?submissionId=50741 - article about the extreme variability in cesarean rates among Brazilian hospitals

Evidence-Based Information About Cesareans

• http://www.childbirthconnection.org/article.asp?ck=10166 - evidence-based review of the pros and cons of cesarean birth. Written in plain language, with research citations available 
• http://www.childbirthconnection.org/article.asp?ck=10164&ClickedLink=274&area=27 - What Every Pregnant Woman Needs to Know About Cesarean Section, booklet/PDF by Childbirth Connection 
• Optimal Care in Childbirth: The Case for a Physiologic Approach, by Henci Goer and Amy Romano (MSN, CNM). Seattle: Classic Day Publishing, 2012.  Copies may be ordered from www.optimalcareinchildbirth.com.