A review of policies on alcohol use during pregnancy in Australia and other English-speaking countries, 2006

To the Editor: O’Leary and colleagues1 rightly point to the need for better evidence on whether low to moderate maternal alcohol intake affects the fetus. Evidence to date is weak and inconsistent, largely because alcohol consumption in pregnancy is generally poorly documented,2 and few studies have recorded data on factors that could potentially modify fetal exposure. Evidence could come from large pregnancy cohort studies, usually designed to address other issues, but there are no published guidelines on how to collect information relevant to fetal alcohol exposure during gestation. There is, therefore, a great need to define a core dataset for research studies, as well as one that is sufficiently simple to use in routine pregnancy care settings.

We have identified a number of issues that need to be addressed. To stimulate discussion, the Box shows our suggested core dataset.

Maternal alcohol intake: Alcohol questionnaires have largely been designed to identify women who are heavy drinkers, misuse alcohol or are alcohol-dependent.3 Questionnaires are needed that capture information on alcohol intake across the range, from minimal to heavy drinking, as well as information on drinking patterns and alcohol intake at different periods of gestation.

Factors that may modify the relationship between maternal intake and fetal alcohol exposure: For a given maternal intake over a given period, maternal blood alcohol level and hence fetal alcohol exposure may vary according to maternal size and body composition. Other factors can affect maternal alcohol absorption and elimination, such as whether alcohol is taken with food,4 and possibly maternal genotype.5 This information is rarely reported in pregnancy studies.

Factors that may modify effects of alcohol on the fetus: There is animal evidence that maternal micronutrient supplementation may protect the fetus against some of the adverse effects of gestational alcohol exposure.6 We need to consider recording supplement use and measures of maternal nutritional intake or status. In well resourced studies, fetal genotype could also be considered.6

Researchers with expertise in the field need to reach consensus and provide guidelines on the best way to assess fetal alcohol exposure, so that pregnancy researchers and clinicians with little experience of alcohol research do not need to create their own. Better data should provide better evidence on which to base advice to women who are (or may be) pregnant. Good studies may also provide explanations for the apparently variable link between maternal alcohol consumption and adverse sequelae in the offspring.