The Relationship Between Pregnancy Exposure to Antidepressant and Atypical Antipsychotic Medications and Placental Weight and Birth Weight Ratio: A Retrospective Cohort Study.

BACKGROUND

Psychotropic medication use in pregnancy has been associated with altered fetal growth. The aim of this study was to investigate the relationship between placental weight and placental weight-to-birth weight (PBW) ratio, as a potential marker of placental efficiency, and medication use in a cohort of women with severe mental illness in pregnancy.

METHODS

A retrospective database analysis was carried out on a cohort of pregnant women with severe mental illness (242 singleton pregnancies) and grouped according to their psychotropic medication use. Demographic, obstetric, neonatal, and psychiatric variables were analyzed using t tests, χ, analysis of variance, univariate, binary, and multiple regression adjusting for potential confounders.

RESULTS

Multiple regression analysis demonstrated a mean adjusted increase in placental weight of 114 g (95% confidence interval [CI], 60.2-165.6 g) in women taking antidepressant medication and 113 g (CI, 65.1-162.8 g) in women taking combined antidepressant and atypical antipsychotic medication in pregnancy. There was also a significantly elevated PBW ratio in these 2 medication groups (B 0.02: CI, 0.006-0.034; and B 0.025: CI, 0.012-0.038). Binary regression, adjusted for sex and gestational age, showed a significant odds ratio of 4.57 (95% CI, 2.17-9.62) for PBW ratio of greater than 90% in those taking antidepressant medication, either alone or in combination, compared with unmedicated women.

CONCLUSIONS

The use of antidepressant medication, alone or in combination, has a significant effect on placental weight and PBW ratio after adjusting for confounding variables. Given that this may reflect adverse effects on intrauterine growth and have possible long-term implications for the fetus, further research is warranted to confirm these findings.