Association of Exposure to Phthalate Metabolites with Antenatal Depression in US Pregnant Women

Antenatal depression affects 10-20% of pregnant women, with notable adverse outcomes for the neonates. Limited studies have indicated a potential link between exposure to phthalate metabolites and depression. The association between phthalate metabolites and depression in pregnant women is unknown. We sought to evaluate the association of exposure to phthalate metabolites with depression severity score in US pregnant women. This cross-sectional study used data collected by the National Health and Nutrition Examination Survey during 2005-2018 on pregnant adults who completed urinary profiles that examined 12 common phthalate metabolites. Linear and quantile sum regressions were used to evaluate the association between depressive symptoms (measured by the Patient Health Questionnaire, PHQ-9) and concentrations of phthalate metabolites. A total of 208 women were included in the analysis. These women's mean (SD) age was 27.42 (5.78) years. We found that all the phthalates were associated with PHQ-9 scores except for mono (carboxyoctyl) and mono-isononyl phthalate. Similar results were observed with the association of high levels of phthalates with mild, moderate, and severe depression (PHQ-9 >4 vs. ≤4). All the phthalate metabolites remained significantly associated with depression scores in the adjusted analysis. Among all considered phthalate metabolites, a combination of MCNP, MBP, MiBP, MnBP, and MEHP contributed to the strongest association with higher depression scores. The relative importance was similar for MCNP (weight = 0.32) and MBP (weight = 0.31), followed by MiBP (weight = 0.12), MnBP (weight = 0.08), MEHP (0.07), and MEP (weight = 0.04) for depression scores. Our findings suggest that pregnant women with high exposure to phthalates are more likely to have higher depressive symptom scores.