Head Injuries Related to Birth Trauma in Low Birthweight Neonates During Vacuum Extraction.

Abstract

Introduction Preterm delivery (gestational age <34w) is a relative contraindication to vacuum extraction. Current data do not differentiate clearly between preterm delivery and low birthweight. We aimed to evaluate the impact of non-metal vacuum cup extraction on neonatal head injuries related to birth trauma in newborns with low birthweights (<2500g). Materials and Methods A retrospective cohort of 3377 singleton pregnancies delivered by vacuum extraction from 2014 to 2019. All were gestational age ≥34w. We compared 206 (6.1%) neonates with low birthweights <2500g to 3171 (93.9%) neonates with higher birthweights, divided into 3 subgroups (2500-2999g, 3000-3499g, and ≥3500g). A primary composite outcome of neonatal head injuries related to birth trauma was defined. Results The lowest rates of subgaleal hematoma occurred in neonates <2500g (0.5%); the rate increased with every additional 500g of neonatal birthweight (3.5%, 4.4% and 8.0% in the 2500-2999g, 3000-3499g, and ≥3500g groups, respectively; p=0.001). Fewer cephalohematomas occurred in low birthweight neonates (0.5% in <2500g), although the percentage increased with every additional 500g of birthweight (2.6%, 3.3% and 3.7% in the 2500-2999g, 3000-3499g, and ≥3500g groups, respectively, p=0.020). Logistic regression found increasing birthweight to be a significant risk factor for head injuries during vacuum extraction, with adjusted odds ratios of 8.12, 10.88, and 13.5 for 2500-2999g, 3000-3499g, and ≥3500g, respectively (p=0.016). NICU hospitalization rates were highest for neonates weighing <2500g (10.2%) compared to the other groups (3.1%, 1.7% and 3.3% in 2500-2999g, 3000-3499g, ≥3500 respectively, p<0.001). Conclusions Vacuum extraction of neonates weighing <2500g at 34w and beyond seems to be a safe mode of delivery when indicated, with lower rates of head injury related to birth trauma, compared to neonates with higher birthweights.