Maternal antibiotic exposure is associated with decreased mammary IgA and IgM 3948

Abstract Description Broad spectrum antibiotics are being increasingly used in obstetric patients without long term follow up on neonatal risks. Previous data have suggested antibiotics for preterm premature rupture of membranes increases neonatal late onset sepsis and nectrozing enterocolitis (NEC), but the mechanism is unknown. We analyzed samples from the Mechanisms of Maternal Immunoglobulin A control over the neonatal microbiota and the development of NEC (MAMI) trial. MAMI enrolled infants born under 32 weeks and collected maternal-infant biospecimens. We performed a detailed chart review for maternal antibiotic exposure and analyzed breast milk samples collected 10-45 days post delivery by ELISA. Data were compared by t test and one way ANOVA. Breast milk IgA was higher than IgG and IgM (p < 0.0001, p < 0.005). When compared by antibiotic exposure, IgA and IgM were decreased with any antibiotic exposure (p = 0.02, p = 0.01). IgA was decreased by length of antibiotic exposure (p = 0.02). We stratified by the antibiotic spectrum of activity into narrow (penicillin, ampicillin) and broad (2nd and 3rd generation cephalosporin, gentamicin, etc) and found that the spectrum of antimicrobial activity was associated with a decrease in maternal IgA with broad spectrum antibiotics with the least amount of IgA (p < 0.004). Our data demonstrate mammary IgA and IgM are decreased with antenatal antimicrobial exposure. These data suggest a mechanism by which antenatal antibiotics may lead to neonatal sepsis and NEC. Topic Categories Mucosal and Regional Immunology (MUC)