The role of sonographic head circumference in the occurrence of subgaleal hemorrhage following vacuum delivery.

Objective: Subgaleal hemorrhage (SGH) is a severe neonatal morbidity that is associated with vacuum-assisted delivery (VAD). Large sonographic head circumference (sHC) was previously associated with complicated VAD. Nevertheless, the association of large sHC with SGH formation following VAD is underreported. We aim to evaluate the role of sonographic head circumference (sHC) with SGH formation following attempted VAD.
Methods: A retrospective case-control study. Cases comprised singleton pregnancies for whom attempted VAD resulted in SGH with an sHC measured within 2 weeks from delivery. Controls were VAD deliveries which not resulted in SGH, with an sHC measured within 2 weeks from delivery. We matched controls in a 1:1 ratio by gestational age, parity and year of delivery.
Results: Overall, 118 women were included in the SGH study group and were matched to 118 controls. Baseline maternal and fetal characteristics were similar between the groups except for higher neonatal birth weight in the SGH group (median 3422 vs. 3195 grams, p  = .001). sHC did not vary between groups (median 336 mm in SGH groups vs. 333, p  = .08). Rate of sHC >90th and >95th percentile did not significantly differ between the groups (13.6% vs. 8.5%, 6.8% vs. 3.4%, p  = .21, p  = .37, for SGH vs. controls, respectively). In multivariate regression analysis, sHC was not found to be independently associated with SGH - aOR (95% CI) 1.004 (0.97-1.03). Receiver operating characteristic curves of sHC for SGH formation underlined an area under the curve of 0.58 (95% CI) (0.51-0.65).
Conclusions: sHC is not associated with SGH formation following VAD.