The Pima infant feeding study: the role of sociodemographic factors in the trend in breast- and bottle-feeding

Abstract
In 1978, a retrospective study of the influence of sociodemographic factors on the trend in breast- and bottle-feeding was conducted among a sample of Pima Indian women 15 to 44 yr old residing on the Gila River Reservation. Based on interviews with 257 Pima Indian women about their infant feeding experiences, the proportion of women who breast-fed dropped significantly between 1949 and 1977. The decline in breast-feeding was evident among women aged 35 to 44 in 1978 across three socioeconomic strata; while women aged 30 to 34 experienced an increase in breast-feeding across two socioeconomic strata. Between 1949 and 1963, women of 50 to 100 and 100% Pima Indian descent breast-fed significantly less than those with other tribal affiliations; however, the influence of tribal descent was reduced thereafter. Bottle-feeding was more prevalent in the high birth orders over time. Among women with first births before 1963, those with small families bottle-fed more than those with large families across birth order. Conversely, among women with first births during or after 1963, those with large families bottle-fed more than those with small families across birth order.