(HealthDay)—Combined drinking and smoking after the first trimester of pregnancy is associated with an increased risk for late stillbirth, according to a study published online Aug. 24 in JAMA Network Open.
Hein Odendaal, M.D., from Stellenbosch University in Cape Town, South Africa, and colleagues examined whether prenatal exposure to alcohol and tobacco cigarettes is associated with the risk for stillbirth among pregnant women from Cape Town and the Northern Plains region of the United States.
The researchers found that women reported no alcohol or tobacco cigarette exposure in 51 percent of pregnancies (risk for stillbirth, four per 1,000 pregnancies). Eighteen percent of women drank and smoked after the first trimester, 9 percent only drank, and 22 percent only smoked (risk for stillbirth, 15, 10, and eight per 1,000 pregnancies, respectively). Compared with the reference group (without prenatal exposure or exposure after the first trimester), the adjusted relative risk for late stillbirth was 2.78 (95 percent confidence interval, 1.12 to 6.67), 2.22 (0.78 to 6.18), and 1.60 (0.64 to 3.98) for pregnancies prenatally exposed to drinking and smoking, drinking only, and smoking only, respectively, after the first trimester; the corresponding adjusted relative risks for all stillbirths were 1.75 (0.96 to 3.18), 1.26 (0.58 to 2.74), and 1.27 (0.69 to 2.35).
"This new finding of the association between stillbirth and combined prenatal exposures to drinking and smoking is important given the extensive documentation that alcohol is frequently used in combination with tobacco cigarettes, including by pregnant women," the authors write.
One author disclosed financial ties to UpToDate and the publishing industry.
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