February 22, 2017

expert reaction to research on schizophrenia and insufficient weight gain in pregnancy

Publishing in JAMA Psychiatry researchers report that gestational weight gain (GWG) was associated with an increased risk for nonaffective psychosis in offspring.

Prof. Sir Robin Murray FRS, Professor of Psychiatric Research at the Institute of Psychiatry, Psychology and Neuroscience, King’s College London, said:

“This is a competent large study with rigorous methodology which takes advantage of the wonderful Swedish birth and hospital records.  It builds on lots of other evidence suggesting that a range of prenatal and perinatal events increase the risk of schizophrenia and similar psychoses.  For example, we know that babies born very premature or following very long labour are at increased risk.

“In the past it has been shown that children who were in utero at the time of severe famine are more likely to develop schizophrenia than expected.  It is therefore not so surprising that insufficient weight gain by mothers during pregnancy can also increase later risk of later schizophrenia spectrum disorders in offspring, presumably by subtly impairing the development of the baby’s brain.  Of course this study does not pin-point the cause of the lack of weight gain. Malnutrition is an obvious candidate but maternal illness leading to the lack of weight gain is also possible.

“But this does not mean pregnant women should overeat, and the advice remains the same.  Eat a balanced diet and keep healthy during pregnancy. Take folic acid and don’t smoke tobacco or use illicit drugs.

“We should not get carried away into thinking this is the major factor in the cause of schizophrenia-like psychosis. Genetic predisposition, child abuse and adverse life events as well as abuse of drugs like cannabis all contribute.”

* ‘Association of Gestational Weight Gain and Maternal Body Mass Index in Early Pregnancy With Risk for Nonaffective Psychosis in Offspring’ by Euan Mackay et al. published in JAMA Psychiatry on Wednesday 22 February 2017.

Declared interests

None declared