Submitted to: Journal of Reproductive Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/1998
Publication Date: N/A
Citation: Interpretive Summary: A woman's immunity to illness is reduced during pregnancy. Lactating women recover from this syndrome while secreting immunologically active agents into milk. We wanted to know whether maternal breastfeeding behavior or serum prolactin levels are correlated with measures of immunity in lactating women. We found a correlation between breastfeeding activity and maternal immune status: the beneficial effects lasted longer. Percentages of CD19+ B-cells were correlated inversely with prolactin levels and number of breastfeeding sessions in the previous 24 hours. These results suggest that exclusive breastfeeding has a greater potential to modify the mother's health than the partial breastfeeding often practiced in the United States. Further, lactation plays an important role in the immune system's transition from pregnancy to full postpartum immunocompetence.
Technical Abstract: PROBLEM: Lactating women recover from pregnancy-induced immunosuppression while actively secreting immunologically active agents into milk. Few clinical studies have examined changes in postpartum maternal immune status or explored mechanisms. METHOD OF STUDY: We measured blood B-cell (CD19+) percentages and serum concentrations of immunoglobulin (Ig) G, IgM, and IgA at 1 to 2 weeks, 1 month, and 2 months postpartum in a longitudinal study of seven healthy, lactating women. RESULTS: More frequent or extended breast-feeding sessions were correlated with lower CD19+ percentages, reduced serum IgG, and higher serum IGA and IgM concentrations. CD19+ percentages were correlated negatively with serum prolactin concentrations. Blood samples drawn before and 30 min after breast-feeding did not differ in CD19+ percentages or serum Ig concentrations. CONCLUSIONS: These findings confirm our previous cross-sectional study showing a negative correlation between CD19+ percentages and serum prolactin. Because lactation practices are modifiable, these findings suggest that women can influence the course of lactation-associated immunologic changes.