MedWire News: The risk of fatal birth defects is higher among children born to women with schizophrenia than in those born to women without a serious mental illness, researchers have found.

Explaining the reasons for their study, Dr R Webb, from the University of Manchester in the UK, and team write: “Few large studies describe links between maternal mental illness and risk of major birth defect in offspring. Evidence is sparser still for how effects vary between maternal diagnoses and no previous study has assessed risk with paternal illnesses.”

To address this, the researchers studied data on around 1.45 million children who were born between 1973 and 1998 in Denmark. They used psychiatric information to identify all parents who had previously been admitted to hospital for a serious mental health illness, and used hospital records to identify all children who died due to birth defects.

The researchers found that 2.4% of the children had a mother who had been admitted for a psychiatric illness and 2.3% a father who had been admitted for a mental health condition.

In total, 3867 of the children had fatal birth defects.

Analysis revealed that children with mothers who had been admitted for any type of mental illness were 1.35 times more likely to have a fatal birth defect than those with mentally healthy mothers.

However, this risk was even higher for children with mothers who suffered from schizophrenia. Indeed, such children were 2.34 times more likely to have a fatal birth defect than other children.

A paternal history of psychiatric conditions was not associated with the risk of fatal birth defects in offspring.

Writing in the journal Psychological Medicine, Dr Webb and team conclude: “There are many possible explanations for a higher risk of fatal birth defect with maternal schizophrenia.

“These include genetic effects directly linked with maternal illness, lifestyle factors (diet, smoking, alcohol and drugs), poor antenatal care, psychotropic medication toxicity, and gene–environment interactions.”

They add that further research is now needed to clarify and tackle the causes of fatal birth defects in children born to women with serious mental health disorders.