Maternal colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae in term versus preterm pregnancies

Objectives: To examine the prevalence and risk factors of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) colonization among women who delivered preterm and at term. Methods: A prospective observational study of maternal ESBL-E rectovaginal colonization in threatened preterm labor and low-risk term pregnancies was conducted between March 2017 and August 2021 at the Galilee Medical Center, Israel. Obstetric and neonatal complications were compared between colonized and non-colonized mothers and neonates. Results: ESBL-E colonization was similar in the preterm (n = 202) and term (n = 172) groups: 14.4% and 16.9%, respectively (P = 0.567). The maternal-neonatal transmission rate was higher in the preterm than the term group but the difference was not statistically significant: 42.1% and 22.2%, respectively (P = 0.42). Prematurity was a risk factor of neonatal ESBL-E colonization (odds ratio 1.33, 95% confidence interval 1.01–1.75, P = 0.041). ESBL-E-colonized preterm infants were delivered at an earlier gestational age and were more likely to have complications. Maternal ESBL-E colonization and transmission were more prevalent in pregnancies complicated by threatened preterm labor or premature rupture of membranes than in term pregnancies. Conclusions: These findings emphasize the need for further research on the cost-effectiveness of screening for maternal ESBL-E colonization in preterm labor, to prevent neonatal infectious complications. ClinicalTrials.gov identifier NCT03251885.