Alcohol Drinking During Pregnancy

Alcohol Drinking During Pregnancy

Critique 020.  New data on effects of alcohol during pregnancy. 12 October 2010

Reference: Kelly YJ, Sacker A, Gray R, Kelly J, Wolke D, Head J, Quigley MA.  Light drinking during pregnancy: still no increased risk for socioemotional difficulties or cognitive deficits at 5 years of age?  J Epidemiol Community Health 2010; doi:10.1136/jech.2009.103002.

A very large population-based observational study from the UK found that at the age of 5 years, the children of women who reported light (no more than 1-2 units of alcohol per week or per occasion) drinking did not show any evidence of impairment on testing for behavioral and emotional problems or cognitive ability.  There was a tendency for the male children of women reporting “heavy/binge” drinking during pregnancy (7 or more units per week or 6 or more units per occasion) to have poorer behavioral scores, but the effects were less clear among female offspring.

Scientific data continue to indicate that higher intake of alcohol during pregnancy may adversely affect the fetus, and could lead to very severe developmental or other problems in the child.  However, most recent publications (as does this one) show little or no effects of occasional or light drinking by the mother during pregnancy.  They also demonstrate how socio-economic, education, and other lifestyle factors of the mother may have large effects on the health of the fetus and child; these must be considered when evaluating the potential effects of alcohol during pregnancy.

Overall, current scientific data indicate that while drinking during pregnancy should not be encouraged, there is little evidence to suggest that an occasional drink or light drinking by the mother is associated with harm.  Heavy drinking, however, may be associated with serious developmental defects in the fetus.

Addendum: After the above critique was prepared, a new paper has been published on the topic by O’Leary et al (O’Leary CM, Nassar N, Kurinczuk JJ, de Klerk N, Geelhoed E, Elliott EJ, Bower C.  Prenatal Alcohol Exposure and Risk of Birth Defects  Pediatrics 2010;126;e843-e850; DOI: 10.1542/peds.2010-0256).  Overall, the results of that study are similar to those of the study by Kelly et al, with no increase in risk of birth defects in children born of women reporting low or moderate drinking during pregnancy but with an increased risk of defects among children of women reporting heavy drinking.