Mothers-to-be, Beware! Smoking during pregnancy increases risk of schizophrenia in kids

Smoking during pregnancy may increase the risk of schizophrenia in your baby, a new study has warned. Researchers from Columbia University (CU) in the US evaluated nearly 1,000 cases of schizophrenia and matched controls among offspring born in Finland from 1983-1998.

Results showed that a higher maternal nicotine level in the mother's blood was associated with an increased risk of schizophrenia among their offsprings, researchers said. The study provides the most definitive evidence to date that smoking during pregnancy is associated with schizophrenia, they said.

Heavy maternal nicotine exposure was associated with a 38 per cent increased odds of schizophrenia, researchers said. "To our knowledge, this is the first biomarker-based study to show a relationship between foetal nicotine exposure and schizophrenia," said Alan Brown from CU. 

Heavy smoking based on cotinine, a reliable marker of nicotine in maternal sera, was reported by 20 per cent of the mothers of cases, but only 14.7 per cent of the mothers of controls, researchers said. Smoking during pregnancy is known to contribute to significant problems in utero and following birth, including low birth weight and attentional difficulties, they said. 

Nicotine readily crosses the placenta into the foetal bloodstream, specifically targets foetal brain development, causing short- and long-term changes in cognition, and potentially contributes to other neurodevelopmental abnormalities, researchers said. 

"These findings underscore the value of ongoing public health education on the potentially debilitating, and largely preventable, consequences that smoking may have on children over time," said Brown. The findings were published in the journal American Journal of Psychiatry.