BackgroundBecause maternal depressive symptoms and stress during pregnancy are strongly associated with poor health of the mother and the developing child, understanding the predictors of women’s mental health problems is important to prevent complications in the perinatal period. Therefore, this study sought to examine the association between six risk factors – gestational weight gain (GWG), low physical activity, sleep problems, alcohol use, cigarette smoking and snack food intake – and mental health problems during pregnancy. We hypothesized that risk factors would predict mental health problems while adjusting for socio-demographic characteristics and pregnancy intention, both cross-sectionally and longitudinally.MethodsHierarchical linear regression analyses were conducted in a population-based sample of N = 463 pregnant women during their 2nd trimester (gestational age: 23 to 28 weeks) of whom n = 349 were reassessed during their 3rd trimester (gestational age: 33 to 38 weeks). Women had a mean age of 29.8 ± 4.2 years and a mean pregravid body mass index of 23.5 ± 4.3 kg/m2. Data were collected by the ‘Leipzig Research Center for Civilization Diseases’ via the Patient Health Questionnaire, Pittsburgh Sleep Quality Index, Food Frequency Questionnaire, self-report items on physical activity and substance use, and objectively measured anthropometrics.ResultsCross-sectionally, while a higher snack food intake and sleep problems predicted depressive symptoms and stress during the 2nd trimester, gestational weight gain predicted stress only. Longitudinally, sleep problems positively predicted depressive symptoms during the 3rd trimester. All results remained significant after controlling for age, pregravid body mass index, and pregnancy intention. GWG and significant longitudinal effects became insignificant when controlling for gestational age or baseline depressive symptoms and stress, respectively.ConclusionsThe results showed that sleep problems were associated with maternal mental health problems during pregnancy. Longitudinal studies using standardized measures, particularly diagnostic interviews and physiological or biochemical markers, are warranted to confirm patterns of risk factors, their association with depressive symptoms and stress during the course of pregnancy, and their effects on mother’s and child’s health.