(P10-063-24) Breastfeeding Intensity and Its Association With Mammary Gland Involution Early Post-partum Among Mothers in Low-Income Households

Objectives: To examine breastfeeding pattern early postpartum (first six weeks) and the association between breastfeeding intensity and mammary gland involution markers (Lactose and Protein levels) among racially and ethnically diverse group of mothers living in low-income households.

Methods: Pregnant women in their third trimester were recruited from a local prenatal clinic (n =25). The two key selection criteria were: 1) eligible or participating in WIC; 2) intended to breastfeed. Upon birth/hospital discharge, six weekly home visits were conducted to collect human milk samples and carry out 24-hour feeding recalls. Breastfeeding intensity was computed as the number of daily breastfeeds divided by the number of total feeds. To assess markers of involution, bicinchoninic acid assays were used to measure protein concentrations in breast milk samples, while Megazyme assays were utilized to determine lactose levels.

Results: By race/ethnicity of 25 mothers,12 were African American while 7 were of Latino origin. One-fourth of the mothers were primiparous and 88% had a vaginal delivery. Overall, more than half of the mothers (64%) were doing exclusive breastfeeding by week 6 postpartum. Latino mothers were more likely to do mixed feeding with 5 out of 7 were doing it by week 3 postpartum. Among African American mothers, 67% were doing exclusive breastfeeding at week 6 postpartum. Milk-feeding status at week 2 after birth was a significant predictor of feeding status at week 6 (p < .05). In examining mammary gland involution markers, we found that the percent change in milk protein concentration over the first 6 weeks after birth was negatively correlated with the intensity of breastfeeding (r = -0.5860; p = 0.0026), while the % change in lactose concentration was positively correlated with breastfeeding intensity (r = 0.6420; p = 0.0007).

Conclusions: Racial/ethnic differences exist in breastfeeding intensity, and establishing exclusive breastfeeding status at 2 weeks is a significant predictor of its continuation. Our study also provides evidence of involution of the mammary gland among women doing mixed feedings. Future research is warranted into whether mixed feeding is associated with poor lactation support and stress among a racially/ethnically diverse group of low-income mothers.

Funding Sources: NIH-NICHD