By Georgia Ragonetti-Zebell, MD
Does Pitocin cause postpartum depression? If you believe headlines like these (“Pitocin Use May Increase Risk of Postpartum Depression”), you might think so. But a closer look at the study reveals the headlines are not always what they seem.
The study appeared in the journal Depression and Anxiety and noted an association between synthetic oxytocin (US brand name: Pitocin) and postpartum mood disorders. Let’s review the actual numbers.
This is a retrospective study, meaning it looks at events that have already happened. Charts were reviewed for one medical system between 2005 and 2014. 46,732 women were identified who had one or more deliveries in the time frame. Of these, 9,684 had pitocin within 2 weeks of delivery and 37,048 did not. The pitocin may have been for induction, a contraction stress test (stimulating contractions while monitoring the baby to make sure the baby can tolerate labor), or postpartum hemorrhage.
Among women who had pitocin, there was a 32% increase in postpartum mood disorder (36% increase if mom had a history of a postpartum mood disorder). This increase held true whether the birth was the first or second, whether it was term or preterm and whether it was vaginal or cesarean delivery.
So, if there is an increase in postpartum mood disorders, doesn’t that mean that pitocin causes depression? Not necessarily. Just because two things are linked does not mean one is causing the other. The classic example is ice cream sales and shark attacks. When ice cream sales go up, so do shark attacks. Obviously, the ice cream sales are not the cause of the shark attacks, merely an indicator of summertime, when folks hit the beach and are therefore more likely to encounter a shark. In that case, the headline shouldn’t read, “Eating Ice Cream May Increase Risk of Shark Attack” because that’s not true.
This study is an example of a correlation. Pitocin use in women is correlated with postpartum depression, but that doesn’t necessarily mean that it causes depression. In fact, there are a number of reasons why the correlation may exist.
Oxytocin, sometimes called the “love hormone” is responsible for those loving feelings mommas get when they see their babies. Oxytocin levels in women with postpartum depression have been found to be lower than levels in women without postpartum depression. This “love hormone” is also responsible for uterine contractions. Postdate, or overdue, pregnancies and “failed inductions” have been shown to have decreased levels of oxytocin receptors. Perhaps these low oxytocin levels and decreased receptors are the reason why the patient needed pitocin for induction or augmentation of labor in the first place. Obstetric complications in general increase the risk of postpartum depression. Many of those complications involve treatment with pitocin.
Just like the ice cream in the shark attack example, the need for synthetic oxytocin use may simply be a marker for those with already low levels or low levels of receptors.
A more helpful study would randomize women to elective induction or spontaneous labor and then compare subsequent postpartum mood disorders. That might help tease out some of the questions about whether the pitocin is causing the depression or merely being used in women who have decreased oxytocin levels or receptors to help with labor progress, who also happen to be at risk for depression.
Still, this study is important, even if it isn’t quite what the headlines made it out to be. While all postpartum women need to be screened for depression, knowing which mommas needed pitocin for an obstetric complication will help healthcare providers identify women who may be at increased risk for postpartum depression.
If you are having symptoms of postpartum depression, whether you had pitocin or not, see your healthcare provider right away. You are not alone, mommas.
Georgia Ragonetti-Zebell, MD is an OB/GYN practicing in Upstate South Carolina, and is mommy to four (yes, FOUR) boys. She is a graduate of the Women’s Health Pathway at Drexel University College of Medicine in Philadelphia, Pennsylvania and completed her residency in Obstetrics and Gynecology with the Greenville Health System in Greenville, South Carolina. She has a special interest in natural childbirth, breastfeeding, and alternative methods in labor and delivery. She enjoys yoga, crochet, and reading, but spends most of her free time cleaning up poop while trying not to step on Legos.