Effect of instrument preference for operative deliveries on obstetrical and neonatal outcomes

To examine the relationship between physicians' instrument preference and obstetrical and neonatal outcomes.

A retrospective cohort study comparing obstetrical and neonatal outcomes of second stage deliveries between obstetricians who prefer forceps (forceps >/=90%) with obstetricians with no preference to forceps (either instrument <90%) was completed using the McGill Obstetrical and Neonatal Database. Logistic regression analysis was used to obtain an adjusted odds ratio controlling for maternal, intrapartum and neonatal confounders.

Two thousand and three hundred thirteen infants were delivered by 5 obstetricians who preferred forceps, and 9261 infants were delivered by 15 obstetricians with no instrument preference. Baseline characteristics were similar between the two groups. As compared to obstetricians who preferred forceps, obstetricians with no instrument preference had a higher rate of operative vaginal deliveries 1.5 (1.1-2.0), a higher cesarean section rate 2.5 (1.3-4.9) and a higher episiotomy rate in non-operative vaginal deliveries 3.4 (2.7-4.3). Infants delivered by obstetricians with no instrument preference were less likely to have significant bruising 0.3 (0.2-0.6) but more likely to have a cephalohematoma 3.0 (1.1-8.3).

Physician instrument preference is an important determinant of outcomes that should be considered in studies evaluating instrumental deliveries.