Patterns of variation in breast-feeding behaviors

This paper describes the range and patterning of variation in specific breast-feeding behaviors among a sample of 62 American mothers, as well as the relationship of the patterns to duration of exclusive breast feeding. Infant feeding data were collected using 24-hr records completed by mothers every 8 days through the first 6 months post partum. Behaviors examined were: number of daily feedings, minimum and maximum intervals between feedings, length of feedings and total daily nursing duration. Variation in magnitude of these behaviors ranged from three- to eight-fold. Principal components analysis found this variation patterned in two dimensions, relating to feeding frequency and length of time spent breast feeding. These dimensions accounted for approximately equal proportions of variance in the breast-feeding behaviors, totaling about 80% of all variance at 4 and 8 weeks. There was significant continuity of breast-feeding styles practiced by any one woman from 4 to 8 weeks. The feeding frequency dimension was strongly associated with duration of exclusive breast feeding. Three explanations--cultural, biological and biocultural--are proposed to account for this association. It is argued that the intracultural variation in breast-feeding styles in this sample may be sufficient to cause corresponding variation in breast milk production, in part accounting for variation in duration of exclusive breast feeding. Predictions of exclusive breast-feeding duration will be most accurate for women with a breast-feeding style of infrequent feedings, while predictions for women with a style of frequent feeding will be confounded by cultural factors which have an independent effect on breast-feeding supplementation.