Preterm assisted vaginal births and associated maternal and neonatal outcomes: A retrospective study in a tertiary hospital.

OBJECTIVES

This study compares maternal and neonatal outcomes between preterm vacuum and forceps-assisted vaginal births and evaluates preterm outcomes between those <34 + 0 weeks gestation to those ≥34 + 0.

METHODS

This study is a single-center retrospective cohort study of all singleton assisted vaginal births during 2014-2021. Delivery data and data on neonatal and pregnant patient outcomes were extracted from electronic medical records. Categorical variables were described by frequencies and percentages, and adjusted odds ratios (aORs) were calculated using logistic regression.

RESULTS

There were 5095 assisted vaginal births during this period, of which 246 were preterm (171 vacuum and 75 forceps assisted). Neonatal head ultrasounds were less common after preterm vacuum- than after preterm forceps-assisted births (6.4 vs. 13.3%). Of those under 34 weeks (18 vacuum and 18 forceps assisted), there were identical rates of head ultrasound in each group (n = 7, 38.9%). Rates of Grade 1 intraventricular hemorrhage were the same between the vacuum- and forceps-assisted groups under 34 weeks (n = 5, 27.7%). No major intra- or extra-cranial bleeds were found among infants who underwent a vacuum- or forceps-assisted birth before 34 weeks. Maternal outcomes showed significantly lower odds of obstetric anal sphincter injury (aOR 0.26) and episiotomy (aOR 0.16) with preterm vacuum compared to preterm forceps-assisted births.

CONCLUSION

This study adds to a small but growing body of literature that supports maternal and neonatal safety of vacuum-assisted birth under 34 weeks' gestation, in comparison with the use of forceps, when assisted vaginal birth is required. Larger prospective registry-based studies are suggested to determine the robustness of this conclusion.