Wednesday, February 4, 2015

Another Reason Not to Schedule a Pre-Labor Cesarean

Here is an interesting recent study showing that women who had a scheduled pre-labor cesarean had an increased risk for Placenta Previa (low-lying placenta, near or over the mouth of the cervix) in a subsequent pregnancy.

Although rare, previas present significant risks to both mothers and babies. These include severe hemorrhage and hysterectomy for the mother, as well as prematurity, breathing issues, and the need for Neonatal Intensive Care Units (NICU) for the baby. That's why it's important to reduce the risk for previas whenever possible.

The important finding in this large, multiple-hospital study was that women had a higher risk for previa if they had a pre-labor cesarean than if they had a vaginal birth or a cesarean that occurred after the start of labor. 

Although the risk for previa was increased in women who had a cesarean that occurred during labor, this increase did not rise to statistical significance.

But the risk for previa after a pre-labor cesarean was more than doubled. That's a troubling finding, and suggests that we should not take scheduled cesareans lightly.

This may be particularly important finding for very high-BMI women, who are increasingly scheduled for pre-labor "elective" cesareans without any chance at labor.

Of course, there are legit reasons to schedule a pre-labor cesarean. A small increase in the chance of previa in the next pregnancy does not justify avoiding a pre-labor cesarean if one is truly indicated.

However, if there is no true medical need for a pre-labor cesarean (and BMI does not qualify as a legit reason), then this is yet another reason not to just schedule an elective cesarean before labor.

More and more data indicates that labor is beneficial for both mom and baby...and in this case, possibly for future pregnancies as well.


Am J Obstet Gynecol. 2015 Jan 7. pii: S0002-9378(15)00005-8. doi: 10.1016/j.ajog.2015.01.004. [Epub ahead of print] Prior Prelabor or Intrapartum Cesarean Delivery and Risk of Placenta Previa. Downes KL1, Hinkle SN2, Sjaarda LA2, Albert PS3, Grantz KL4. PMID: 25576818
OBJECTIVE: To examine the association between previous cesarean delivery and subsequent placenta previa while distinguishing cesarean delivery prior to onset of labor from intrapartum cesarean delivery. STUDY DESIGN: Retrospective cohort study of electronic medical records from 20 Utah hospitals (2002-2010) with restriction to the first two singleton deliveries of women nulliparous at study entry (n=26,987). First pregnancy delivery mode was classified as 1) vaginal (reference); 2) cesarean delivery prior to labor onset (prelabor); or 3) cesarean delivery after labor onset (intrapartum). Risk of second delivery previa was estimated by prior delivery mode using logistic regression and adjusted for maternal age, insurance, smoking, co-morbidities, prior pregnancy loss, and history of previa. RESULTS: The majority of first deliveries were vaginal (82%, n=22,142), followed by intrapartum cesarean delivery (14.6%, n=3,931), or prelabor cesarean delivery (3.4%, n=914). Incidence of second delivery previa was 0.29% (n=78) and differed by prior delivery mode: vaginal, 0.24%; prelabor cesarean delivery, 0.98%; intrapartum cesarean delivery, 0.38% (P<0.001). Relative to vaginal delivery, prior prelabor cesarean delivery was associated with an increased risk of second delivery previa (adjusted odds ratio, 2.62 [95% confidence interval, 1.24-5.56]). There was no significant association between prior intrapartum cesarean delivery and previa [adjusted odds ratio, 1.22 (95% confidence interval, 0.68-2.19)]. CONCLUSION: Prior prelabor cesarean delivery was associated with a more than two-fold significantly increased risk of previa in the second delivery, while the approximately 20% increased risk of previa associated with prior intrapartum cesarean delivery was not significant. Although rare, the increased risk of placenta previa after prior prelabor cesarean delivery may be important when considering non-medically indicated prelabor cesarean delivery.

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