Association of antidepressant use with obesity risk in pregnant women: a retrospective cohort study.

Objective: This study evaluated the relationship between treatment for depression and anxiety in pregnancy and the risk of obesity.

Design: Multivariate logistic regression analysis, nested case control study design.

Setting: Births occurring 2008-2022 at an outer-suburban, lower socioeconomic maternity hospital in Australia. Population: 75,308 eligible births. Main outcome measures: BMI ≥ 30 (obesity), BMI ≥ 35 (severe obesity/obesity class II and III).

Results: In this analysis, we found an adjusted OR of 1.56 of BMI ≥ 30, p < .000 with CI (1.35-1.80) in women taking antidepressants in pregnancy, OR 1.56 of BMI ≥ 35, p < .000, CI (1.31-1.84). Within this dataset, a cohort of 7559 women with a history or current diagnosis of depression or anxiety were found; adjusted OR of 1.40 of BMI ≥ 30, p < .000, CI (1.22-1.60) in women within this group taking antidepressants. Rates of severe obesity were similar in this cohort, BMI ≥ 35; OR 1.39, p < .000; CI 1.18-1.62).

Conclusions: These results suggest an increase in rates of obesity in women taking antidepressants in pregnancy not accounted for by other risks for obesity which might accrue from current mental ill-health or other cohort effects such as genetic vulnerability or lifestyle factors. This outcome is important in relation to the care of pregnant women with depression and anxiety. In view of current high rates of prescribing of antidepressants in pregnancy and the postpartum, this research may help inform clinician decision-making for women at risk of obesity in pregnancy.