Maternal Colonization of Extended-Spectrum-Beta-Lactamase-Producing Enterobacteriaceae in Preterm Rupture of Membranes

Aim: Maternal colonization by Enterobacteriaceae that produce extended-spectrum β-lactamases (ESBL-E) has risen, and the antimicrobial resistance of ESBL-E is significant. We aimed to evaluate the rates of ESBL-E colonization among women with preterm premature rupture of membranes (PPROM) and of maternal-neonatal vertical transmission. We also aimed to compare obstetrical and neonatal complications among ESBL-E positive versus negative maternal colonization in pregnancies complicated by PPROM.

Methods: This retrospective study included women with PPROM who were admitted during 2018-2022 for expectant management and were screened for ESBL-E recto-vaginal colonization on their admission. Obstetrical and neonatal outcomes were compared between positive and negative ESBL-E pregnancies. Neonatal outcomes were compared between positive and negative ESBL-E neonates.

Results: Of 118 women with PPROM, 27 (23%) had positive ESBL-E cultures. ESBL-E isolates (cultures from the placenta, cord, amnion, or uterus) were more common in colonized versus non-colonized ESBL-E mothers (55.6% versus 11.0%, P < 0.001). ESBL-E isolates were more common in neonates of mothers with positive versus negative ESBL-E cultures (33.3% versus 4.2%, P = 0.017). A higher proportion of neonates of ESBL-E positive than ESBL-E negative mothers needed antibiotic treatment in the neonatal intensive care unit. Neonatal ESBL-E colonization at birth was a predictor of longer stay in the neonatal intensive care unit (P = 0.006).

Conclusions: In women with PPROM, maternal-ESBL-E colonization was a significant risk factor for neonatal colonization and was associated with neonatal morbidity. The high maternal colonization rate in PPROM raises the need for routine maternal ESBL screening. Future studies should establish the ideal empiric antibiotic regimen in the NICU for neonates born to ESBL-E colonized mothers.