Alcohol and pregnancy: little evidence about the effect on the fetus

A review of the medical literature failed to demonstrate a significant effect of occasional drinking during pregnancy on the fetus mass consumption, except the possible deleterious effect on neurodevelopment.

The authors of this review recommend anyway, given the lack of evidence, as a precaution to avoid this behavior during pregnancy, pending further study. Conversely, if a patient reports an episode, outside of regular heavy alcohol consumption, it is important to avoid her unnecessary anxiety that may be harmful to pregnancy.

Studies in animals have suggested that this was the maximum concentration of alcohol in the blood at any given time rather than the average consumer who determined the significance of the observed lesions on the fetus.

Jane Henderson of the University of Oxford and his colleagues selected 14 relevant studies of 3630 titles and abstracts of observational studies on the topic identified between 1970 and 2005.

They collected data on the impact of binge drinking, usually defined by the consumption of five or more drinks on one occasion, 60 g of alcohol on miscarriage, stillbirth, delayed intrauterine growth, prematurity, low birth weight and birth defects, including fetal alcohol syndrome and neurological development.

"There was constantly significant effect of alcohol on any of the criteria considered," the authors say. However, "there was a possible effect on neurodevelopment."

Four studies assessed neurodevelopment. One has found that a higher degree of "disinhibited behavior" in children whose mothers drank heavily and occasionally alcohol during pregnancy.

Another reported a significant decrease in verbal IQ and an increase in delinquent behavior. Yet another found more learning problems and poorer performance lasting up to 14 years. The fourth found nothing.

"In the absence of a strong research base on which to establish any strong clinical recommendations, we suggest to prioritize research on the occasional massive consumption of alcohol during pregnancy," the authors conclude.