Factors associated with perceived insufficient milk in a low-income urban population in Mexico.

Survival analysis and logistic regression were used to identify factors associated with the onset of perceived insufficient milk among 165 healthy mothers who planned to breast-feed and gave birth by vaginal delivery, without complications, to a healthy term infant in either a nursery (n = 58) or a rooming-in-hospital where formula supplementation was not allowed (n = 107). Women were interviewed in the hospital and at 1 wk, 2 mo and 4 mo postpartum. Women from both hospitals were similar in socioeconomic, demographic, anthropometric, previous infant feeding experience and prenatal care variables. Eighty percent of the women reported perceived insufficient milk at some point during the study. The cue interpreted most often as indicating insufficient milk was the crying of the infant. Multivariate analyses indicated that lack of confidence in breast-feeding, delayed onset of milk production, maternal education, multiparity, sore nipples, early introduction of formula to the previous child and mother breast-fed as a child were significantly associated (P < 0.05) with perceived insufficient milk. Among women who reported perceived insufficient milk before 1 wk, breast-feeding confidence and maternal education interacted with the hospital in which they delivered.