Protracted vacuum extraction and neonatal intracranial hemorrhage among infants born at term: a nationwide case-control study.

Abstract

The association between vacuum extraction and intracranial hemorrhage has been debated. We sought to investigate the impact of protracted vacuum extraction on the risk for neonatal intracranial hemorrhage in term infants. This nationwide case-control study covered Swedish maternity wards from 1999 to 2013. All term, live-born infants diagnosed with neonatal intracranial hemorrhage after vacuum-assisted delivery were included as cases (n=167). For each case, 3 vacuum-delivered controls, without a diagnosis for intracranial hemorrhage, were selected (n=546 controls). Conditional logistic regression analysis was used to study the association between protracted extraction (defined as vacuum duration >15min, >6 pulls or >2 cup detachments), and neonatal intracranial hemorrhage. Extractions exceeded 15min among 33% of the cases, vs 5% of the controls. More than six pulls were used in 25% of the cases and in 4% of the controls, and more than two cup detachments occurred in 3.6% of the cases and in 0.6% of the controls. Compared with extractions adhering to safety recommendations, the odds for intracranial hemorrhage were nine-fold (OR 8.91, 95%, CI 5.22-15.20) among infants exposed to a protracted extraction. After adjustments for potential confounders, the OR decreased to 8.04 (95% CI 4.49-14.38). The strong association between protracted extraction and intracranial hemorrhage suggests that adherence to safety recommendations may reduce the risk for intracranial hemorrhage in infants delivered by vacuum extraction. However, safe limits for vacuum duration and number of pulls are still unknown and intracranial hemorrhage may occur even when performed in accordance with safety recommendations.