Maternal complications and risk factors associated with assisted vaginal delivery

OBJECTIVE: This study aimed to elucidate the maternal complications and risk factors linked with assisted vaginal delivery. METHODS: We conducted a retrospective, descriptive analysis of hospital records, identifying 3500 cases of vaginal delivery between 2020 and 2022. Data encompassing demographics, complications from the vaginal delivery including post-partum haemorrhage, birth passage injuries, puerperal infection and other pertinent details were documented. Various critical factors, including the duration of the second stage of labor, maternal anemia, underlying maternal health conditions such as diabetes mellitus and hypertension, neonatal birth weight, maternal weight, the expertise of the attending surgeon, and the timing of deliveries were considered. RESULTS: The rates for assisted vacuum and forceps delivery were 6.0% (211/3500 cases) and 0.3% (12/3500), respectively. Postpartum haemorrhage emerged as the predominant complication in vaginal deliveries, with a rate of 7.3% (256/3500; P < 0.001). Notably, postpartum haemorrhage had significant associations with gestational diabetes mellitus class A1 (adjusted odds ratio [AOR] 1.46; 95% confidence interval [CI] 1.01–2.11; P = 0.045), assisted vaginal delivery (AOR 5.11; 95% CI 1.30–20.1; P = 0.020), prolonged second stage of labour (AOR 2.68; 95% CI 1.09–6.58; P = 0.032), elevated maternal weight (71.4 ± 12.2 kg; AOR 1.02; 95% CI 1.01–1.03; P = 0.003) and neonates being large for their gestational age (AOR 3.02; 95% CI 1.23–7.43; P = 0.016). CONCLUSIONS: The primary complication arising from assisted vaginal delivery was postpartum haemorrhage. Associated factors were a prolonged second stage of labour, foetal distress, large-for-gestational-age neonates and elevated maternal weight. Cervical and labial injuries correlated with neonates being large for their gestational age. Notably, puerperal infections were related to maternal anaemia (haematocrit levels < 33%). CLINICAL TRIAL REGISTRATION: Thai Clinical Trials Registry: 20220126004.