Factors influencing milk insufficiency and its long-term health effects: the Bedouin Infant Feeding Study

Abstract

Women who breastfeed have frequently reported milk insufficiency as the reason for introducing the bottle, but no one has addressed its potential long-term health effects. This paper described the factors associated with milk insufficiency versus another reason for introducing the bottle and its potential health effects based on an analysis of a prospective cohort study of 1005 Bedouin Arab women who delivered healthy newborns in 1981 and 1982. By two months postpartum, 72% introduced the infant to the bottle with 72% reporting milk insufficiency as the reason for introducing the bottle. The percentage of milk insufficiency declined with increasing age of the infant. Based on multiple logistic regression analyses, birth season was statistically significantly associated with the odds ratio (OR) of milk insufficiency versus another reason for introducing the bottle during the first two months. Women who delivered in the spring-summer had an increased OR = 1.65 of reported milk insufficiency compared with those who delivered during the rest of the year. Parity was directly related to the OR = 1.04 of milk insufficiency (but just missed significance) during one to two months and was statistically significantly associated with the OR = 1.12 of reported milk insufficiency during 3-18 months. The rates of stunting after the infant was introduced to the bottle and the duration of breastfeeding did not differ by reason for introducing the bottle. Thus the high frequency of reported milk insufficiency was not associated with adverse health effects.

PIP: 1005 Bedouin infants born in 1981-1982 at the Soroka Medical Center Hospital in the Negev, Israel were followed up determine those factors which influence milk insufficiency reporting compared with another reason and the possible effects of the reported reason for introducing the bottle on the rates of stunting and the duration of any breastfeeding. 72% of the mothers had already started bottle feeding their infants by 2 months as did those who claimed to have had insufficient milk. After 2 months, however, the rate of inadequate milk as a reason declined. For example, 50% gave milk insufficiency as a reason at 3-6 months postpartum and 28% at 7-18 months postpartum. Infants born in March-July were at significantly higher risk of being introduced to the bottle with milk insufficiency as the reason in the 1st 2 months of life than those born in other months (odds ratio [OR]=1.65). In early infancy, parity was just slightly related to milk insufficiency (OR=1.04). Yet multiparous women with a 3-18 month index child were more likely to state milk insufficiency as a reason to begin bottle feeding than primiparous mothers (OR=1.12). This was a result of a change from a seminomadic life style to a sedentary life style. Specifically, even though settling in urban areas brought them closer to family and the family visited more often during the traditional 40-day postpartum rest period, assistance during this period fell or was nonexistent. Further, household chores increased. Multiparous mothers needed a rest between breastfeeds and introducing the bottle allowed them this rest. Thus they gave milk insufficiency as justification for this behavior regardless of its occurrence or not. Neither the rates of stunting among infants introduced to the bottle nor duration of breastfeeding differed by reason for introducing the bottle. Thus the high rates of reported milk insufficiency did not adversely affect their health.