A new perspective on the causal pathway between maternal mental health and neonatal adversity

Substantial evidence suggests a downstream impact of maternal mental health on birth outcomes. The roles of comorbid maternal physical health and familial confounding underlying this association remain unclear.

This cohort study included a random sample of children born 1997-2008 within a health maintenance organization (HMO) in Israel, their parents, and siblings. Outcomes were ICD-9 diagnoses of neonatal adversities (birth complications and congenital anomalies) and exposures were maternal diagnoses of mental health disorders. Odds ratios (ORs) and their 95% confidence intervals for the associations between maternal mental health diagnoses and measures of neonatal adversity were calculated using logistic regression, adjusting for maternal age, child's year of birth, socioeconomic status, and maternal physical morbidity burden. We examined potential familial confounding using a negative control approach based on paternal exposure.

In our sample of 74,533 children, 6,674 (9.1%) were born after birth complications and 14,569 (19.9%) with a congenital anomaly. Maternal mental health diagnosis around pregnancy was significantly associated with these measures of neonatal adversity after adjustment for potential confounders (birth complications: OR = 1.3 (1.2-1.4), p < 0.001; congenital anomalies: OR = 1.2 (1.1-1.3), p < 0.001). These associations became attenuated and non-significant after further adjustment for maternal physical morbidity burden. In a joint model, maternal and paternal diagnosis of a mental health disorder were independently associated with neonatal adversity (birth complications: OR_mat=1.3 (1.1-1.4), p < 0.001; OR_pat=1.2 (1.1-1.3), p = 0.004; congenital anomalies: OR_mat=1.2 (1.1-1.3), p < 0.001; OR_pat=1.1 (1.0-1.2), p = 0.01).

Physical health and familial factors play a role in the associations between maternal mental health and neonatal adversity.