Multiple modifiable lifestyle factors and the risk of perinatal depression during pregnancy: Findings from the GUSTO cohort

Background: Studies have identified lifestyle risk factors for perinatal depression, but none have examined the cumulative effect of these risk factors in pregnant women. Methods: We considered the following six factors during pregnancy: poor diet quality (Healthy eating index for Singapore pregnant women<median), poor sleep quality (global Pittsburgh sleep quality index score > 5), physical inactivity (<600 MET-minutes/week), vitamin D insufficiency (<50 nmol/l), smoking before or during pregnancy, and the perceived need for social support. Probable depression was assessed using the Edinburgh postnatal depression scale during pregnancy (>15) and at three months postpartum (≥13). Prevalence risk ratios were calculated with Poisson regressions while adjusting for potential confounders. Results: Of 535 pregnant women, 207 (39%) had zero or one risk factor, 146 (27%) had two, 119 (22%) had three, 48 (9%) had four, and 15 (3%) had ≥5 risk factors at 26–28 weeks' gestation. These six lifestyle habits contributed to 32% of the variance in depressive symptoms during pregnancy. The prevalence of being probably depressed was 6.4 (95% CI 2.1, 19.8; p _trend < 0.001) for expecting women who had ≥4 risk factors compared to women who had ≤1 risk factor. No association was observed between the number of risk factors and depressive symptoms at 3 months postpartum (p _trend = 0.746). Conclusion: Pregnant women with ≥4 lifestyle risk factors showed a higher prevalence of depression during pregnancy, while no associations were observed for postpartum depression. Clinical trial registration: This cohort is registered under the Clinical Trials identifier NCT01174875; http://www.clinicaltrials.gov/ct2/show/NCT01174875?term=GUSTO&rank=2