Pathways for Intellectual Disability in Children: Maternal Mental Illness vs Obstetric Complications

There is a significant association between maternal severe mental illness and intellectual disability in children according to a study published in The American Journal of Psychiatry. Investigators also found a significantly heightened risk for developing intellectual disability in children who have been exposed to obstetric complications of critical severity.

Investigators identified 15,351 children and mothers with severe mental illness and 449,229 children born to mothers without mental illness between 1980 and 2001.  A total of 6217 children with an intellectual disability were born to mothers with severe mental illness. The risk for developing intellectual disability was higher in mothers with severe mental illness vs mothers without. Children born to mothers with schizophrenia had the highest unadjusted odds of intellectual disability (odds ratio [OR] 3.8; 95% CI, 3.0-4.9).  The odds were also increased in children born to mothers with bipolar disorder, unipolar disorder, depression, or any other psychotic disorder.

Investigators also observed an increased risk for intellectual disability associated with obstetric complications during each period of exposure, including pregnancy, labor and delivery, and the neonatal period. In addition, the researchers found that for children with familial heightened risk, the odds ratio of intellectual disability of a genetic basis was 2.0 (95% CI, 1.5-2.7) compared with children with generic risk.

Investigators also observed that in children with intellectual disability, 4.2% developed a psychotic disorder compared with 1.1% of children without intellectual disability.

The researchers point to the study as strong evidence for considering maternal severe mental illness and obstetric complications to be related — and occasionally overlapping —  but separate causes of intellectual disability in children. The investigators concluded that although maternal mental illness and obstetric complications seem to be related in some respects, “the impact of obstetric complications should be considered separately from the effect of maternal severe mental illness.”

Reference

Di Prinzio P, Biostat M, Morgan V A, et al. Intellectual disability and psychotic disorders in children: Association with meternal severe mental illness and exposure to obstetric complications in a whole-population cohort. Am J Psychiatry. doi:10.1176/appi.ajp.2018.17101153