Pregnant women who smoke cigarettes and drink alcohol may put their babies at higher odds for Sudden Infant Death Syndrome (SIDS), a new government study finds.
After the first trimester of pregnancy, women who both smoked and drank increased the risk for SIDS nearly 12 times. For those who continued to smoke, SIDS risk rose fivefold, and for those who continued to drink, the risk was four times higher, researchers found.
The risks are compared with women who didn't use tobacco or alcohol before getting pregnant or who stopped by the end of the first trimester.
"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," said study co-author Amy Elliott. She is chief clinical research officer at Avera Health Center for Pediatric and Community Research in Sioux Falls, S.D.
For the study, researchers followed nearly 12,000 pregnancies in five U.S. sites, including two American Indian reservations in the Dakotas, and in Cape Town, South Africa. These sites were selected because they have high rates of alcohol use and SIDS.
Between 2007 and 2015, 66 infants died, including 28 from SIDS and 38 from other causes.
The study was supported by the National Institute on Alcohol Abuse and Alcoholism, part of the U.S. National Institutes of Health.
"Our findings support the current recommendation of the U.S. Centers for Disease Control and Prevention, the U.S. Surgeon General, and the World Health Organization that women not drink or smoke during pregnancy, and emphasizes the significance of dual exposure, which provides the greatest risk for infant mortality," co-author Dr. Hannah Kinney said in an NIH news release. Kinney is a neuropathologist at Boston Children's Hospital.
The report was published online recently in the journal EclinicalMedicine.
To learn more about SIDS, visit the U.S. Centers for Disease Control and Prevention.