Smoking and drinking while pregnant increases risk of SIDS

It has already been shown that smoking during pregnancy increases the risk of Sudden Infant Death Syndrome (SIDS) dramatically. But findings from a recent study suggest that combining that habit with alcohol consumption can make matters even worse.

Researchers funded by the National Institutes of Health (NIH) say that pregnant women who continue to smoke and drink alcohol into the first trimester are more likely to bear children who are in danger of succumbing to SIDS. 

"Ours is the first large-scale prospective study to closely investigate the association between prenatal alcohol and tobacco exposure and the risk of SIDS," said Dr. Amy J. Elliot, the study’s first author. "Our findings suggest that combined exposures to alcohol and tobacco have a synergistic effect on SIDS risk, given that dual exposure was associated with substantially higher risk than either exposure alone."

Alcohol and smoking dramatically increases risk

The research team came to their conclusions after analyzing the outcomes of nearly 12,000 pregnancies. In total, 66 children died after one year -- with 28 deaths being attributed to SIDS. 

While 28 in nearly 12,000 may not seem like a high death rate to some, the researchers noted that the children of pregnant women who drank alcohol and smoked after the first trimester of pregnancy were 12 times more likely to die of SIDS when compared to other children. On their own, smoking or drinking beyond the first trimester increased risk of SIDS by five and four times, respectively. 

The researchers say these results support recommendations by health officials that women avoid alcohol and tobacco during pregnancy, and that is especially true for dual exposure.

"These findings provide still more evidence of the vital importance of the early prenatal environment to healthy postnatal outcomes. Insofar as many women quit drinking and smoking only after they learn that they are pregnant, this study argues strongly for screening for substance use early in pregnancy and intervening as soon as possible,” NIH officials said in a statement. “It also calls for stronger public health messaging regarding the dangers of drinking and smoking during pregnancy, and among women who plan to become pregnant."

The full study has been published in the journal EclinicalMedicine.