COMPARATIVE ANALYSIS OF NEONATAL AND MATERNAL MORBIDITY IN VACUUM-ASSISTED VERSUS FORCEPS-ASSISTED OPERATIVE VAGINAL DELIVERIES

Prof. Jakob Andersson; MD; PhD; Dr. Linnea Berg; MD

Abstract

This comparative study evaluates the differential impact of vacuum-assisted delivery (VAD) versus forceps-assisted delivery (FAD) on immediate maternal and neonatal outcomes within a tertiary care setting. Operative vaginal delivery remains a critical intervention for managing prolonged second-stage labor and fetal distress, yet the selection between instruments is often debated regarding specific morbidity profiles. Our investigation utilized a retrospective cohort of 940 singleton pregnancies, rigorously analyzing the incidence of high-grade perineal lacerations, postpartum hemorrhage, and neonatal trauma. The abstract details how while vacuum extraction is associated with a lower incidence of severe maternal perineal trauma, it correlates with a higher frequency of neonatal cephalohematoma and retinal hemorrhages. Conversely, forceps delivery demonstrates superior success rates in completing the delivery but poses significant risks for third- and fourth-degree perineal tears. These findings provide a nuanced clinical framework for obstetricians to weigh maternal pelvic floor integrity against neonatal cranial safety during instrumental interventions. The data underscores the necessity for individualized decision-making based on operator proficiency and specific fetal-maternal risk factors to optimize obstetric results.

Keywords: Operative Vaginal Delivery, Forceps Extraction, Vacuum-Assisted Delivery, Obstetric Anal Sphincter Injuries (OASI), Neonatal Cephalohematoma, Maternal Morbidity, Perineal Lacerations

As the global rates of primary cesarean sections continue to rise, the preservation of skills in operative vaginal delivery is paramount for reducing surgical morbidity. However, the choice of instrument remains a point of contention among obstetricians and mid-tier practitioners. This research is highly relevant to the AAMS Maternal & Reproductive Health Conference as it provides evidence-based data on the trade-offs between maternal and neonatal safety. With the increasing focus on patient-centered care and the long-term implications of pelvic floor trauma (such as fecal incontinence and prolapse), understanding the higher OASI risk associated with forceps is crucial. Conversely, the rising awareness of neonatal safety protocols makes the quantification of vacuum-related cranial injuries essential for informed consent. This study bridges the gap between clinical practice and patient outcomes, offering a data-driven approach to reducing preventable delivery complications in specialized obstetric units.

The primary objective of this study was to compare the rates of maternal birth canal trauma and neonatal intracranial/extracranial injuries between vacuum-assisted and forceps-assisted deliveries in a contemporary obstetric population.

A retrospective cohort study was conducted at a high-volume University Hospital between January 2019 and December 2023. A total of 940 patients who underwent instrumental delivery were identified: 580 underwent VAD (using a specialized silastic cup) and 360 underwent FAD (using Simpson or Neville-Barnes forceps). Inclusion criteria were singleton, cephalic, term pregnancies (≥37 weeks) with a documented indication for instrumental assistance. Exclusion criteria included multifetal gestations and breech presentations. Maternal outcomes measured were third- and fourth-degree perineal tears (OASI), postpartum hemorrhage (>500mL), and vaginal wall hematomas. Neonatal outcomes included Apgar scores at 1 and 5 minutes, admission to the Neonatal Intensive Care Unit (NICU), cephalohematoma, subgaleal hemorrhage, and facial nerve palsy. Statistical analysis was performed using SPPS v26.0, employing Chi-square tests for categorical variables and independent t-tests for continuous data. Logistic regression was utilized to calculate Odds Ratios (OR) with 95% Confidence Intervals (CI), adjusting for maternal age, parity, and birth weight.

Analysis of 940 deliveries revealed significant differences in morbidity. Forceps-assisted delivery (FAD) was associated with a significantly higher rate of OASI (14.2% vs. 4.3% in VAD; OR 3.65, 95% CI 2.41–5.54, p < 0.001). Maternal postpartum hemorrhage occurred in 11.5% of FAD cases compared to 7.8% in the VAD group (p = 0.04). However, VAD exhibited a higher failure rate, with 8.4% requiring transition to a second instrument or cesarean section, compared to only 1.9% in the FAD group (p < 0.001). Regarding neonatal outcomes, cephalohematoma was significantly more common in the VAD group (9.1% vs. 2.8% in FAD; OR 3.48, 95% CI 1.72–7.05, p < 0.005). Low Apgar scores (<7 at 5 min) were recorded in 3.1% of VAD and 2.5% of FAD cases, which did not reach statistical significance (p = 0.58). NICU admission rates were comparable (6.2% VAD vs. 5.6% FAD). Facial nerve palsy was exclusively noted in the FAD group (1.1%, n=4).

The study concludes that both vacuum and forceps are effective tools for labor management, but they carry distinct, non-overlapping morbidity profiles. Vacuum-assisted delivery is the safer modality for the maternal perineum, significantly reducing the risk of permanent pelvic floor dysfunction and severe lacerations. However, the increased risk of neonatal extracranial hemorrhage necessitates vigilant pediatric monitoring post-delivery. Forceps delivery remains highly effective for rapid extraction but requires advanced surgical skill to mitigate the documented high risk of maternal OASI. We recommend that clinical guidelines prioritize vacuum extraction as the first-line instrumental intervention unless maternal factors or fetal position specifically indicate the mechanical advantages of forceps. Furthermore, the high 'failure-to-extract' rate in the vacuum group suggests that clinicians must be prepared for emergency cesarean section or a cautious trial of forceps if the initial vacuum application is unsuccessful.