Effects of maternal pre-pregnancy body mass index and gestational weight gain on antenatal mental disorders in China: a prospective study

BackgroundMaternal obesity is the most common medical condition among women of reproductive age worldwide. The pre-pregnancy body mass index and gestational weight gain have been suggested to be associated with maternal mental disorders. This study aimed to investigate the effects of the pre-pregnancy body mass index and gestational weight gain on antenatal depression, stress, and anxiety.MethodsIn total, 4,890 pregnant women were enrolled in the present study, which is based on an ongoing prospective cohort study. We used self-reported pre-pregnancy weights and the last weights measured prior to delivery (using professional instruments) to calculate the pre-pregnancy body mass index and gestational weight gain. The questionnaires used included the Center for Epidemiologic Studies Depression Scale (CES-D), Self-Rating Anxiety Scale (SAS), and 10-item version of the Perceived Stress Scale (PSS-10). We used Pearson product-moment correlation and multivariable logistic regression models to examine the impact of the pre-pregnancy body mass index and gestational weight gain on different maternal mental disorders.ResultsAfter adjusting for conception, annual household income, occupation, education, smoking status, and drinking status, excessive gestational weight gain during pregnancy was associated with a greater chance of anxiety symptoms in the entire sample (adjusted model: odds ratio = 1.479, 95% confidence interval = 1.128, 1.938) and especially in women with a normal body mass index (adjusted model: odds ratio = 1.668, 95% confidence interval = 1.209, 2.302). However, the relationship between the maternal pre-pregnancy body mass index and mental health was not significant.ConclusionPregnant women with a normal pre-pregnancy body mass index had a greater chance of experiencing anxiety symptoms before delivery if gestational weight gain was excessive; however, its effects on depression or stress symptoms were not observed. The maternal pre-pregnancy body mass index may not be independently associated with maternal mental disorders.