Maternal bacteremia in intrapartum fever: the role of ampicillin resistance and prolonged membrane rupture-a retrospective comparative study.
Objective: Intrapartum fever (IPF) (≥ 38.0 °C), if treated inappropriately, can lead to maternal bacteremia. In a cohort of women with IPF, we investigated perinatal, obstetrical, and microbiological outcomes, comparing those with bacteremia to those with negative blood cultures.
Methods: A retrospective cohort study at a tertiary hospital (2010-2022) focused on women attempting vaginal delivery who were diagnosed with IPF. Outcomes were compared between those with bacteremia vs. negative blood cultures. After delivery, chorioamniotic swab cultures were obtained. Bacterial distribution and rates of ampicillin-resistant Enterobacteriaceae in blood and swab cultures were described. Women with Group B streptococcal colonization or prolonged rupture of membranes (ROM) received prophylactic ampicillin. The results were compared using univariate and multivariate analysis.
Results: Overall, 78 women had bacteremia, and 341 had negative blood cultures. Women with bacteremia had higher rates of endometritis (p = 0.016), Apgar-5 < 7 (p = 0.021) and umbilical cord pH < 7.1 (p = 0.008). In multivariate analysis, prolonged ROM (p = 0.028) and prophylactic ampicillin (p = 0.036) were linked to maternal bacteremia. Maternal bacteremia (p < 0.001) was associated with higher endometritis and NICU admission rates. Blood cultures and chorioamniotic swab cultures matched in 65.9% of cases. Ampicillin-resistant Enterobacteriaceae spp. were found in 70.2% of blood cultures and 90.6% of chorioamniotic swab cultures. The rate of Enterobacteriaceae-isolated maternal bacteremia was higher among preterm than term deliveries (p = 0.034); while the rate of GBS-isolated bacteremia was lower (p < 0.001).
Conclusions: Ampicillin-resistant Enterobacteriaceae rates in blood and chorioamniotic swab cultures were concerning. Prolonged ROM and prophylactic ampicillin were associated with higher maternal bacteremia rates. Appropriate use of intrapartum antibiotics is essential.