Everything Pregnancy

Another Scary Reason to Quit Smoking During Pregnancy

A new study finds an association between a mother's smoking and an increased risk of her child developing schizophrenia.

pregnant woman in striped shirt smoking Shutterstock
As if you needed another reason to quit smoking during pregnancy, consider new evidence that prenatal nicotine exposure is associated with an increase in a child's risk for developing schizophrenia later in life. In a study published online in the American Journal of Psychiatry, researchers from Columbia University's Mailman School of Public Health, Columbia University Medical Center (CUMC), and New York State Psychiatric Institute and their colleagues in Finland looked at 1,000 people with the disease in Finland to determine the association.

Participants were selected from the large group of pregnant women who were part of the Finnish Prenatal Study of Schizophrenia and matched them with their children who were part of the Finnish Maternity Cohort, which collected over 1 million prenatal blood serum samples between 1983 and 1998, according to Science Daily. After testing prenatal serum for cotinine, a reliable marker of nicotine in maternal blood serum, in both the first and early second trimesters, researchers cross-referenced The Finnish Hospital and Outpatient Discharge Registry for psychiatric hospital admissions and outpatient treatments.

What they found was a strong association between high maternal nicotine levels in the mom's blood and an increased risk of schizophrenia among their children; in fact the child's risk of developing the disease went up 38 percent. Most interestingly is that the link persisted even when researchers controlled for factors like a family history of mental illness.

The study confirms what we already know about nicotine's effects on a fetus: it can cross the placenta and actually enter into the fetal bloodstream, where it impacts birth weight, brain development, and short- and long-term cognition, as well as a host of other functions, including a baby's hormone balance.

"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," explained Alan Brown, M.D., MPH, senior author and Mailman School professor of epidemiology and professor of clinical psychiatry at CUMC, in a news release.

The findings from this study have broader implications as well; researchers can continue to identify biological factors that increase a child's risk of developing other mental disorders, such as bipolar disease and autism.

However, there are caveats to keep in mind, as reporter Amy Ellis Nutt noted in her coverage for The Washington Post: "This is a correlation—as in association—study and so it doesn't answer whether maternal smoking actually causes schizophrenia in offspring. And since smoking rates are known to be higher among people with the diagnosis, it's possible that part of the correlation is due to a kind of self-selection. That is, might pregnant women who smoke and have their own genetic risk factors for schizophrenia be more likely to have children with schizophrenia?"

The most important takeaway is the same news we've been hearing for decades, though: Don't smoke, especially if you're pregnant. Lighting up will adversely affect your child for the rest of his or her life, no if's, and's or butt's.

Melissa Willets is a writer/blogger and a mom. Follow her on Twitter (@Spitupnsuburbs), where she chronicles her love of exercising and drinking coffee, but never simultaneously.