In Reply We read with interest the letter by Uzoigwe and colleagues regarding our article reporting an association between birth by cesarean delivery and offspring risk of obesity.1 The authors of the letter argue that the association reported in our study could be attributed to residual confounding by interpregnancy interval. We disagree. Uzoigwe and colleagues are correct in pointing out that (1) interpregnancy interval is longer among women who deliver by cesarean than among women who deliver vaginally, (2) there is literature suggesting that a shorter interpregnancy birth interval is related to a lower risk of offspring obesity, and (3) the combination of these 2 facts opens the possibility of unaccounted confounding.
Chavarro JE, Yuan C, Gaskins AJ. Obesity and Cesarean Section—Reply. JAMA Pediatr. Published online April 10, 2017. doi:10.1001/jamapediatrics.2017.0391