Objective: To investigate the time-specific effect of maternal exposure to prenatal stressful life events (SLEs) on gestational weight gain (GWG) and to determine whether pre-pregnancy body mass index (BMI) modifies the effect.
Methods: Between March and November 2008, data were collected from 1800 pregnant women who received prenatal check-ups in Hefei, China, after 32 completed weeks of gestation. Participants completed a structured interview on demographic characteristics and a checklist of SLEs during different stages of pregnancy. GWG during pregnancy was determined by self-reported pre-pregnancy weight and measured weight at delivery.
Results: There was a significant dose-response relationship between prenatal SLEs in the first, but not the second or third, trimester and GWG. For each 1-unit increase in SLEs during the first trimester, there was a reduction in GWG of approximately 0.497 kg (95% confidence interval, 0.176-0.817 kg). After stratification by pre-pregnancy BMI, a significant negative association between SLEs in the first trimester and GWG was observed among women with pre-pregnancy normal (β=-0.796; 95% CI, -1.291 to -0.301) and low (β=-1.066; 95% CI, -2.180 to -0.048) weight.
Conclusion: The effect of prenatal SLEs on GWG depends on the timing of maternal exposure to stress and varies according to pre-pregnancy BMI.
Keywords: Body mass index; Gestational weight gain; Life events; Pregnancy; Psychosocial stress.
Copyright © 2013 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.