Kristin Palmsten postdoctoral research fellow, Sonia Hernández-Díaz associate professor, Krista F Huybrechts instructor, Paige L Williams senior lecturer, Karin B Michels associate professor, Eric D Achtyes assistant professor et al
Palmsten K, Hernández-DÃaz S, Huybrechts K F, Williams P L, Michels K B, Achtyes E D et al.
Use of antidepressants near delivery and risk of postpartum hemorrhage: cohort study of low income women in the United States
BMJ 2013; 347 :f4877
doi:10.1136/bmj.f4877
Re: Use of antidepressants near delivery and risk of postpartum hemorrhage: cohort study of low income women in the United States
I am concerned that the obesity data used in this study (a NHANES data set) appears to be non-pregnant data for women of reproductive age. Obesity among women of reproductive age is not the same as obesity at delivery, especially among a depressed cohort. Furthermore, antidepressant medications as well as successful treatment of depression may affect weight gain.
Given that obesity doubles the rate of post partum hemorrhage, controlling for obesity in any study that addresses post partum hemorrhage (PPH) is essential. I am concerned that the external data set introduced an inaccuracy that may have over or underestimated the impact of obesity on PPH among women taking antidepressants at delivery.
More than 50% of pregnant women in America are overweight or obese. To adequately assess the impact of antidepressants on PPH some kind of direct sampling of BMI at delivery was required for a representative sample of the cohort.
Competing interests: No competing interests