The impact of perinatal mental illness on the baby

It is difficult to disentangle the effects of maternal mental disorders on the fetus and child from the effects of genetic contribution, medi­cations, poor parenting, and lifestyle, including smoking, poverty, poor nutrition, and substance use.

Depression during pregnancy is associated with an increased risk of premature delivery, while evidence for birth weight is equivocal (90). Maternal perinatal depression has been associated with emo­tional dysregulation, impaired social skills, internalizing and ex­ternalizing disorders, attachment problems, and increased risk of depression during adolescence (90). It has been hypothesized that the mechanisms underpinning the association between depression in the offspring and maternal antenatal and postnatal depression are different (91). There is little or inconsistent evidence for an effect of perinatal depression on cognitive development (90).

There is a paucity of studies investigating the effects of other mental disorders and evidence is often inconsistent. A study con­ducted on multiparae admitted to mother and baby units found that the risk of psychiatric disorders in adulthood was higher in offspring of puerperal episodes (34%) compared to their siblings from un­affected pregnancies (15%) (92).

The study of the effect of alcohol and illicit substances during pregnancy on the fetus is complicated by the use of multiple sub­stances, comorbidity with other psychiatric disorders, and the as­sociation with disadvantaged socioeconomic status. Teratogenic effects include intrauterine death, dysmorphism, growth restric­tions, and behavioural changes (93).