What is the relationship between alcohol consumption and postnatal growth patterns, sleep patterns and psychomotor patterns of the offspring?

Limited evidence suggests that alcohol consumption during lactation was associated with altered postnatal growth, sleep patterns and/or psychomotor patterns of the offspring.

This conclusion is based on the review of five studies examining the relation of mother’s alcohol consumption during lactation on growth (Backstrand JR et al, 2004), psychomotor development (Little et al, 1989 and Little et al, 2002) and wake and sleep patterns (Mennella JA, Garcia PL, 2001 and Mennella JA, Gerrish CJ, 1998). Backstrand JR et al, 2004 evaluated the effects of pulque (a mildly alcoholic beverage) intake in a prospective cohort of 58 lactating women from rural Central Mexico and found heavier pulque intake during lactation was associated with slower postpartum growth from month one to 57 months (P=0.0054 for weight and P=0.0073 for length). Little et al, 1989 reported that infant motor development at age one, as measured by the Psychomotor Development Index (PDI), was significantly lower in infants exposed regularly to alcohol in breast milk (mother’s alcohol intake of at least 0.5oz per day) with a dose response relation (P=0.006, for linear trend). There was no association found between maternal alcohol use and infant mental development, as measured by the Bayley Mental Development Index. These findings were not replicated by Little et al in 2002 in a sample of 915 18-month age toddlers from the United Kingdom, where infants with the highest alcohol exposure had the highest Griffiths scores in three of five scales, after adjustment for education and other associated factors. Mennella JA, Garcia PL, 2001 and Mennella JA, Gerrish CJ, 1998, using within-subject design studies, found short-term exposure to small amounts of alcohol in mothers’ milk produces distinctive changes in the infants’ sleep-wake patterning.

Growth

Backstrand JR et al, 2004 (positive quality), conducted a prospective cohort study to examine maternal intake of a mildly alcohol beverage (pulque) during pregnancy and lactation, and the potential effect on postpartum child growth and attained size. The study followed 58 mothers and their offspring (from birth to approximately 57 months of age), from rural Central Mexico. Dietary assessment was conducted for two days per month during lactation. A total of 72% of mothers consumed pulque during lactation and the average ethanol intake was 113.8g per week. At month one, the children were relatively short in length, although of average weight-for-age; weight-for-length were well above the reference median. By 57 months, mean length-for-age and weight-for-age had declined substantially. At this age, 52.7% of the children were stunted and 24.1% were underweight. At 57 months, heavier pulque intake during lactation was associated with lower weight (P=0.0242) and length (P=0.0287). Heavier pulque intake during lactation was associated with slower postpartum growth from month one to 57 months (weight, P=0.0054 and length, P=0.0073). In general, the attained size measurements were associated with pulque intake during both pregnancy and lactation, while the child growth measurements were only associated with intake during lactation. In conclusion, pulque intake during lactation may adversely influenced postnatal growth in this population.

Psychomotor Development

Little et al, 1989 (positive quality), conducted a prospective study to investigate the relation of the mother’s intake of alcohol during breastfeeding to the infant’s mental and motor development. Four-hundred infants born to member of a health maintenance organization were evaluated at one year of age. Mental development, as measure by the Bayley Mental Development Index (MDI), was unrelated to maternal drinking during breastfeeding. However, motor development, as measured by the Psychomotor Development Index (PDI), was significantly lower in infants exposed regularly to alcohol in breast milk (after alcohol exposure during gestation was controlled for), with a dose response relation (P=0.006; for linear trend). The infants of breastfeeding mothers who had at least one drink daily (0.5 oz) had a mean PDI score of 98, whereas the infants exposed to less alcohol in breast milk had a mean PDI score of 103 (95% CI for the difference of the two means, 1.2 to 9.8). The effect was strong when mothers who supplemented breastfeeding with formula were excluded from the analysis. The regression analysis showed a predicted decreased of 5.4 points in the PDI for a breastfed infant with an AA score of 1.0, as compared with an infant with no alcohol exposure. In conclusion, ethanol ingested through breast milk has a significantly detrimental effect on motor development in breastfed infants.

Little et al, 2002 (positive quality), conducted a prospective cohort study to evaluate the influence of moderate alcohol use during lactation on the mental development of 915 randomly selected eighteen-month-old toddlers enrolled in a longitudinal population-based study in the United Kingdom. The study used the Griffiths Developmental Scale for the toddlers, and self-administered frequency questionnaires (FFQ) during and after pregnancy to assess alcohol intake. The dose or 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. This dose was compared with the Griffiths Scale of Mental Development, taking into account potentially confounding variables. The Griffiths Scale includes the following measurements: Locomotor, hand and eye coordination, performance test and the General Intelligence Quotient (GQ). Only 5% of mothers had two or more drinks a day during the postpartum period; the average alcohol used was 1.0 or more. Binges in the postpartum period were reported by 37% of all women. For all scales, with the exception of hand-eye coordination and hearing and speech, infants with the highest alcohol exposure via breast milk had the highest Griffiths scores.

Sleep/Wake Patterns

Mennella JA, Garcia PL, 2001 (positive quality), conducted a within-subjects design study to test the hypothesis that infants would compensate less active sleep after exposure of alcohol in their mother’s milk. Twenty-three breast-fed infants from three to five months of age and their mothers were tested on two days, separated by one week. A small, computerized movement detector, an actigraph, was placed on the infants’ left ankles to monitor sleep and activity patterning after which they were bottle-fed mother’s milk alone (control condition) on one test day and mother’s milk containing 32mg of ethanol per 100ml on the other. The infants’ behaviors were monitored for the next 24 hours; the first 3.5 hours of monitoring on each test day took place at the Monell Center. Infants exhibited significantly less active sleep during the 3.5 hours immediately after exposure to alcohol in mothers’ milk compared with the control condition; the decrease in active sleep was observed in all but four of the infants tested. Compensatory increases in active sleep were then observed in the next 20.5 hours, when mothers refrained from drinking alcohol. These findings demonstrate that short-term exposure to small amounts of alcohol in mothers’ milk produces distinctive changes in the infants’ sleep-wake patterning.

Mennella JA, Gerrish CJ, 1998 (positive quality), conducted a randomized control trial (RCT) to test the hypothesis that exposure to alcohol in breast milk affects infants’ sleep and activity levels in the short term. Thirteen lactating women and their infants were tested on two days, separated by an interval of one week. On each testing day, the mother expressed 100ml of milk, while a small, computerized movement detector called an actigraph was placed on the infant’s left leg to monitor sleep and activity patterning. After the actigraph had been in place for 15 minutes, the infants ingested their mother’s breast milk flavored with alcohol (32mg) on one testing day and breast milk alone on the other. The infants’ behaviors were monitored for the next 3.5 hours. The infants spent significantly less time sleeping during the 3.5 hours after consuming the alcohol-flavored milk (78.2 minutes compared with 56.8 minutes after feeding alcohol in breast milk). This reduction was apparently attributable to a shortening in the longest sleeping bout (34.5 compared with 56.7 minutes for sleeping after breast milk alone) and the amount of time spent in active sleep (25.8 minutes compared with 44.2 minutes after breast milk alone); the decrease in active sleep was observed in all but two of the 13 infants tested.