Short-Term Effects of Maternal Alcohol Consumption on Lactational Performance

Milk production, dietary intake, and body composition of 45 lactating women were monitored for 4 months postpartum to examine the interrelationships of these maternal variables. A 3-day dietary record, 24-h test-weighing for determination of milk production, 24-h milk collection, anthropometric measurements, and water displacement for estimation of body fat were performed monthly. The overall mean (SD) energy intake was 2186 (463) kcal/day. Milk production (g/day) averaged 751 (130), 725 (131), 723 (114), and 740 (128) during the 4 sequential months. Weight postpartum was 64.6 (9.1) kg and was 59.3 (10.5) kg at 4 months. Body fat determined by water displacement averaged 28 (7)% at 1 month and 26 (8)% at 4 months. Estimations of body fat from skinfold thickness ranged from 28 (5)% postpartum to 27 (5)% at 4 months. Energy balance calculations based on the energy available from the diet plus the energy derived from tissue mobilization, minus the caloric equivalent of the milk, indicated sufficient energy available for maintenance and activity needs. Thus, it appears that successful lactation is compatible with gradual weight reduction and attainable with energy intakes less than current recommendations.

Beer consumption by nursing women altered the sensory qualities of their milk and the behavior of their infants during breast-feeding in the short term. The infants consumed significantly less milk during the 4-hr testing sessions in which their mothers drank alcoholic beer compared to when the mothers drank nonalcoholic beer; this decrease in milk intake was not due to a decrease in the number of times the babies fed. Although the infants consumed less of the alcohol-flavored milk, the mothers believed their infants had ingested enough milk, reported that they experienced a letdown during nursing, and felt they had milk remaining in their breasts at the end of the majority of feedings. Moreover, the mothers terminated the feeds the same percentage of time on both testing days. The mechanism by which the consumption of alcoholic beer by lactating women decreases milk intake by their nurslings remains to be determined.