Assessment of Alloantibody Presence in Breast Milk of Rh D-Negative Mothers

The study aimed to assess the presence of alloantibody in breast milk of Rh D-negative mothers. This descriptive observational study enrolled Rh D-negative pregnant women with gestational age of ≥ 34 weeks. Two ml of breast milk and 5 ml of maternal EDTA sample were collected within 7 days post-delivery. Indirect Antiglobulin test (IAT) was performed on both samples and if positive, antibody identification and titers were performed. ABO grouping, RhD typing, and Direct Antiglobulin Test (DAT) was performed on neonate's blood sample. Neonates were followed up for the requirement of phototherapy, double volume exchange transfusions (DVET) or PRBC transfusions during their hospital stay and at six-week follow-up. Of 74 mothers enrolled, 30 (40.5%) had positive IAT results in maternal plasma, and 21 (28.4%) had positive IAT in their breast milk. Anti-D was identified in maternal plasma in 29 mothers while 1 had both anti-C and anti-D antibody while only anti-D was identified in the breast milk samples. Anti-D titers ranged from neat to 256 in maternal plasma and from neat to 8in breast milk. A strong positive correlation was observed between anti-D titers in maternal plasma and breast milk (Spearman's correlation coefficient: r_s=0.802, p < 0.001). DAT was positive in 8 neonates. Of these, 3 required both DVET and phototherapy, and 2 required only phototherapy. None of the neonates needed PRBC transfusions. Our study demonstrated presence of alloantibody in breast milk.