Early Weight Gain in Pregnancy and Infant Birth Weight—Reply

In Reply We thank Rigalleau et al for their interest in our study on the association between the timing of maternal weight gain in pregnancy and infant birth weight.¹ In this prospective, preconception cohort study of 1164 women who underwent weight measurement at median 19.9 weeks before pregnancy and then during 10 intervals across gestation, we demonstrated that only weight gain from pregravid to 14 weeks and from 14 to 18 weeks was significantly associated with infant birth weight (while weight gain in the subsequent 8 intervals across pregnancy was not).¹ Rigalleau et al have queried the potential role of gestational diabetes mellitus (GDM) as a basis for our observation of early pregnancy weight gain being associated with subsequent birth weight. They also note that the 1.9% prevalence of GDM in the study was relatively low (which they contrast to a 19.7% prevalence reported in a study from Beijing, China),² and speculate on the potential effect of undiagnosed GDM on our findings.