Umbilical Cord Blood IgA Levels and Bacterial Profile in Preterm Neonates Born with Maternal Risk Factors for Early-Onset Neonatal Sepsis.

Abstract

To investigate the IgA levels and bacterial profile in umbilical cord blood (UCB) samples of mothers with risk factors compared to those without risk factors; and to understand the link between UCB culture positivity and neonatal outcomes [early-onset sepsis (EOS) or death within 7 d of life]. This is a pilot prospective case-control study. Mothers with preterm deliveries (gestational age <34 wk) were enrolled in two groups- Cases: Those with antenatal risk factors (prolonged duration of rupture of membranes of ≥24h or chorioamnionitis) and controls: Those without these two risk factors. Serum IgA levels was assayed and microbiological culture was tested in UCB samples. 16S sequencing to determine the UCB microbiome was performed in a subset of samples (n = 15). Neonates were followed-up for the occurrence of EOS or death until 7 d of life. Forty-nine mothers as cases and 50 mothers as controls were consecutively enrolled. No significant difference was observed in the IgA levels (60.5 vs. 58.1mg/L; p = 0.71), neonatal blood culture positivity (4.1% vs. 8.0%; p = 0.41) and UCB culture positivity (30.6% vs. 26.0%; p = 0.61) in the two groups.No difference was observed between the groups in occurrence of EOS or death within 7 d of life. Proteobacteria, Firmicutes and Actinobacteria were the most abundant phyla. Serratia, Bifidobacterium, Collinsella, Meganomas and Blautia being the most common genera. Cord blood IgA concentration could not differentiate the neonates at-risk of infection due to its presence in both the groups.