In Reply Dr Giannakopoulos raises a valid point that there is uncertainty regarding how cesarean delivery should be incorporated into an analysis of the association between antidepressant medication use late in pregnancy and the risk of PPHN. Multiple roles for cesarean delivery in this analysis are possible: (1) cesarean delivery functions as an intermediate variable on the causal pathway between the exposure and the outcome or (2) cesarean delivery functions as a confounder by sharing a common cause with antidepressant medication use.
Huybrechts KF, Bateman BT, Hernandez-Diaz S. Maternal Antidepressant Use and Persistent Pulmonary Hypertension of the Newborn—Reply. JAMA. 2015;314(12):1294. doi:10.1001/jama.2015.10048