Adverse outcomes in vacuum-assisted delivery after detachment of non-metal cup: a retrospective cohort study

Arch Gynecol Obstet. 2022 Feb;305(2):359-364. doi: 10.1007/s00404-021-06155-y. Epub 2021 Aug 7.

Abstract

Purpose: To evaluate neonatal and maternal outcomes associated with detachment of non-metal vacuum cup during delivery and to identify risk factors for these detachments.

Methods: This retrospective cohort study included women with singleton pregnancy, who underwent vacuum-assisted vaginal delivery with a non-metal vacuum cup in a single academic institution, January 2014-August 2019. Failed vacuum deliveries were excluded. Primary outcomes were defined as subgaleal hematoma (SGH) and cord blood pH < 7.15. Secondary outcome included other neonatal complications and adverse maternal outcomes. Outcomes were compared between vacuum-assisted deliveries with and without cup detachment during the procedure.

Results: A total of 3246 women had successful VAD and met the inclusion criteria. During the procedure, the cup detached at least once in 665 (20.5%) deliveries and did not detach in 2581 (79.5%). The cup detachment group experienced higher rates of SGH (8.9% vs. 3.5%, p = 0.001) and cord blood pH < 7.15 (9.8% vs. 7.1%, p = 0.03). There were also more neonatal intensive care unit admissions (NICU) (4.4% vs. 2.7%, p = 0.03) and more fetuses with occiput posterior position (70.8% vs. 79.4%, p = 0.001), the vacuum duration was slightly longer (6 ± 3.7 vs. 5 ± 2.9 min) and more neonates had birth weights > 3700 g (14.1% vs, 10.3%, p = 0.006). Interestingly, there were more males in that group (60.6 vs. 54.6, p = 0.005). All these factors remained significant after controlling for potential confounders.

Conclusions: Vacuum cup detachment has several predictive characteristics and is associated with adverse neonatal outcomes that should be incorporated into decisions made during the procedure.

Keywords: Cup detachment; Non-metal vacuum cup; Subgaleal hematoma; Vacuum-assisted delivery.

MeSH terms

  • Birth Weight
  • Delivery, Obstetric* / adverse effects
  • Equipment Failure*
  • Female
  • Fetal Blood / chemistry
  • Hematoma, Subdural / etiology
  • Humans
  • Hydrogen-Ion Concentration
  • Infant, Newborn
  • Pregnancy
  • Retrospective Studies
  • Vacuum Extraction, Obstetrical* / adverse effects
  • Vacuum Extraction, Obstetrical* / methods