Abstinence from alcohol before pregnancy and reproductive outcome

Alcohol, breastfeeding, and development at 18 months

OBJECTIVE

We aimed to replicate a previous study of 1-year-olds that reported a deficit in motor development associated with moderate alcohol use during lactation, using a different but comparable population.

METHODOLOGY

The mental development of 915 18-month-old toddlers from a random sample of a longitudinal population-based study in the United Kingdom was measured using the Griffiths Developmental Scales. Frequent self-administered questionnaires during and after pregnancy provided maternal data. The dose of alcohol available to the lactating infant was obtained by multiplying the alcohol intake of the mother by the proportion of breast milk in the infant's diet. We compared this dose with the Griffiths Scales of Mental Development, taking into account potentially confounding variables.

RESULT

Three of the Griffiths scales increased slightly but significantly with increasing infant alcohol exposure; there was no association in the remaining 2 or average of the scales.

DISCUSSION

We were unable to replicate the earlier deficit in motor skills associated with lactation alcohol use. One reason may be that the dose of alcohol reaching the lactating infant is small, and tests of infants and toddlers have limited ability to pick up small effects. Studies of older children may resolve the question of the safety of drinking while nursing.

Low-to-moderate gestational alcohol use and intrauterine growth retardation, low birthweight, and preterm delivery

PURPOSE

Heavy drinking during pregnancy is an established risk factor for fetal alcohol syndrome and other adverse perinatal outcomes. However, there is still debate as to the effects of low-to-moderate drinking during pregnancy.

METHODS

This prospective investigation was based on 2714 singleton live births at Yale-New Haven Hospital during 1988-1992. Alcohol drinking during pregnancy was evaluated with respect to intrauterine growth retardation (IUGR), preterm delivery, and low birthweight.

RESULTS

Mild drinking, defined as > 0.10-0.25 oz of absolute alcohol per day, during the first month of pregnancy was associated with a protective effect on IUGR (OR, 0.39; 95% confidence interval (CI), 0.20-0.76). Overall, drinking during month 1 of pregnancy suggested a curvilinear effect on growth retardation, with consumption of > 1.00 oz of absolute alcohol per day showing increased risk. Drinking during month 7 was associated with a uniform increase in the odds of preterm delivery; the ORs were 2.88 (95% CI, 1.64-5.05) for light drinking and 2.96 (95% CI, 1.32-6.67) for mild-to-moderate alcohol consumption.

CONCLUSIONS

Differences in the risk estimates for IUGR and preterm delivery may indicate etiological differences that warrant further investigation of these outcomes and critical periods of exposure. Low birthweight is not a useful neonatal outcome for this exposure because it is a heterogeneous mix of preterm delivery and IUGR. Despite the observed protective effects of mild drinking on IUGR, the increased risk of preterm delivery with alcohol use supports a policy of abstinence during pregnancy.