Drinking and smoking throughout pregnancy: A lethal combination

Did you know that sudden infant death syndrome is most likely among infants of women who continued to use both tobacco and alcohol beyond the first trimester?

The link between prenatal maternal smoking and sudden infant death syndrome (SIDS) is well established, but an association with maternal alcohol use is less clear. In a prospective longitudinal cohort study, researchers examined potential effects and interactions of exposure to both substances on 12,029 foetuses in Cape Town, South Africa, and two American Indian reservations, locales with high rates of alcohol use and SIDS.

Of pregnancies with known 1-year infant outcomes, 28 (2.4/1000) met criteria for SIDS. Adjusted relative risk for SIDS was 11.8 for pregnancies exposed to both alcohol and tobacco beyond the first trimester compared with no or first trimester–only exposure.

The authors note this is the first study to document the apparent synergistic effects of smoking and drinking on SIDS risk. The encouraging finding is the beneficial effect of stopping these substances before the end of the first trimester — emphasising the importance of offering counselling and quitting resources to reproductive-aged women at every opportunity, especially during preconception and first-trimester visits.