Neonatal complications in vacuum-assisted vaginal delivery: are they associated with number of pulls, cup detachments, and duration of vacuum application?

Purpose: To explore whether the characteristics of vacuum delivery are associated with the occurrence of head injury and neonatal complications. Methods: Retrospectively cohort study of vacuum-assisted attempted vaginal deliveries of singletons. We studied the association of total duration of vacuum application and number of pulls and cup dislodgement with (1) primary outcome: the occurrence of major (subgaleal hemorrhage, skull fracture, and intracranial hemorrhage) or minor (cephalohematoma, scalp laceration more extensive than simple abrasions) neonatal head injuries and (2) secondary outcome: the occurrence of neonatal complications, including 5-min Apgar score <7, umbilical artery pH < 7.10, shoulder dystocia, or need for neonatal intensive care unit admission. Logistic regression analysis was used to control for confounders. Results: Vacuum-assisted delivery was attempted in 555 women. It was successful in 515 cases, and it failed in 40 (7.2 %). Head injury occurred in 32 (6.2 %) of vaginally delivered neonates, and it was related to duration of vacuum application (P = 0.004) and birth weight (P = 0.048). However, the associations lost a statistical significance at the multivariate analysis. Neonatal complications occurred in 25 cases (5 %), and they were associated with meconium-stained amniotic fluid (P < 0.001) and duration of vacuum application (P = 0.03) at the multivariate analysis. However, most of the complications were actually associated with the need for vacuum delivery rather than the procedure itself. Conclusion: Neonatal head injury after vacuum application is not independently related to total duration of vacuum application, number of pulls, or cup dislodgements.