There is no question that high levels of alcohol consumption during pregnancy can lead to severe adverse effects on the fetus, with the most serious condition known as fetal alcohol syndrome (FAS). Many studies have also related alcohol intake during pregnancy with premature birth, low birth weight, and the infant being small for gestational age (SGA). Data are not as clear on the effects just of occasional or light drinking, but most studies have not detected adverse effects.
The present paper, based on a pooled sample of almost 200,000 women from nine European cohorts, provides data indicating that premature birth, an infant being small for gestational age (SGA), or being of low birth weight do not appear to be associated with light-to-moderate intake (up to 6 drinks/week); these results are similar to those from many other recent studies. In this large study, mothers who consumed greater amounts of alcohol tended to have an increased risk of the infant being SGA or with low birth weight, but such a level of drinking had no effect on the risk of premature delivery. This cohort consisted almost exclusively of light drinkers; no data were available on other potentially harmful effects of excessive drinking.
An interesting additional finding was that the reported frequency of any alcohol consumption during pregnancy in the cohorts studied has decreased dramatically in recent decades (from approximately 50% of women studied prior to 2000, to 39% in 2000-2004, to 14% in 2005-2011). This suggests that most women are responding to guidelines recommending that a woman not drink during pregnancy.
Based on currently available information, the Forum considers that a recommendation to “avoid alcohol during pregnancy” is appropriate as part of drinking guidelines for the public. However, scientific data, including the present paper, do not suggest that women who may have an occasional drink or very light alcohol consumption during pregnancy should have undue concern about having a premature birth or a low-birth-weight infant.
Reference: Strandberg-Larsen K, Poulsen G, Bech BH, Chatzi L, Cordier S, et al. Association of light-to-moderate alcohol drinking in pregnancy with preterm birth and birth weight: elucidating bias by pooling data from nine European cohorts. Eur J Epidemiol 2017 pre-publication; DOI 10.1007/s10654-017-0323-2.