Postpartum consequences of an overlap of breastfeeding and pregnancy: reduced breast milk intake and growth during early infancy.

Abstract

OBJECTIVE: Despite cultural pressure to wean when a new pregnancy occurs, some women choose to continue breastfeeding. We determined the effect of an overlap of lactation and late pregnancy on breastfeeding and growth in early infancy. METHODS: We studied 133 Peruvian pregnant women who were > or =18 years of age, had a child <4 years old, and who then had a vaginal birth with a healthy, normal weight infant. Of the 133 women, 68 breastfed during the last trimester of pregnancy (BFP), and 65 had not breastfed during pregnancy (NBFP). On day 2 and at 1-month postpartum, 24-hour intake of breast milk and other liquids was measured. Twice weekly home surveillance documented infant morbidity and dietary intakes. Anthropometry was taken at birth and at 1 month. Maternal anthropometric, health, and socioeconomic status data were collected pre- and postpartum. RESULTS: Pregnant BFP mothers breastfed 5.3 +/- 4.3 times/day. BFP and NBFP infants did not differ in breastfeeding behavior or in colostrum intake on day 2. BFP infants breastfed longer per feed and per 24 hours (35.2 minutes/24 hours) than did NBFP infants; however, 1-month intakes per feed tended to be lower among the BFP infants. After controlling for confounders, BFP infants gained 125 g less than did NBFP infants (about 15% of mean weight gain). A sustained decline would result in a -0.7 z score change in weight-for-age by 6 months. CONCLUSIONS: A lactation-pregnancy overlap had a negative effect on early infant outcomes. Additional studies are needed to determine whether the effect continues past 1 month of age.