Postpartum febrile morbidity following vacuum-assisted birth: A retrospective cohort study

To evaluate whether vacuum-assisted birth (VAB) independently increases the risk of postpartum febrile morbidity, identifying a potentially modifiable contributor to maternal infectious morbidity.

This retrospective cohort study was conducted at a university-affiliated tertiary maternity center between 2011 and 2023. We included women with singleton pregnancies ≥37 weeks of gestation who underwent vaginal birth. Women who underwent VAB formed the study group, while those experiencing spontaneous vaginal birth (SVB) served as the comparison group. To focus on new-onset postpartum febrile morbidity, we excluded women with major intrapartum infectious risk factors, including intrapartum fever, prolonged rupture of membranes (≥24 h), Group B Streptococcus colonization, antibiotic administration during labor, manual removal of the placenta, and third- or fourth-degree perineal tears. Postpartum febrile morbidity was defined as maternal fever (≥38.0°C) occurring between 2 and 48 h after birth, requiring treatment with broad-spectrum antibiotics during hospitalization.

Among 76 958 eligible births, 6137 (7.8%) were VAB and 70 821 (92.2%) were SVB. The VAB group demonstrated a significantly higher rate of postpartum febrile morbidity compared with the SVB group (0.7% vs. 0.2%, P < 0.001). Women undergoing VAB more commonly had nulliparity, epidural anesthesia, longer duration of membrane rupture, prolonged second stage of labor, meconium-stained amniotic fluid, and episiotomy (all P < 0.001). Multivariable analysis confirmed VAB as an independent risk factor for postpartum febrile morbidity (adjusted odds ratio [aOR] 3.01, 95% confidence interval [CI]:1.62-5.61).

VAB is associated with increased risk of postpartum febrile morbidity. These findings support heightened postpartum surveillance and evaluation of preventive strategies following VAB.