Morbidity associated with episiotomy in vacuum delivery: a systematic review and meta-analysis

Background The role of episiotomy in vacuum deliveries is controversial. Objectives To perform a meta-analysis of the literature examining this subject. Search strategy The search was conducted in four databases. Selection criteria Two investigators independently selected original research examining the effects of episiotomy on any neonatal and maternal outcomes during vacuum delivery. Data collection and analysis The effect estimates were presented as odds ratios (ORs) with 95% confidence intervals (95% CIs). Main results Fifteen articles were included, encompassing a total of 350 764 vacuum deliveries. A non-significant relationship was shown between mediolateral episiotomy and obstetric anal sphincter injuries (OASIS) in nulliparous women (OR 0.68, 95% CI 0.43-1.07; six studies), whereas an increased risk was demonstrated in parous women (OR 1.27, 95% CI 1.05-1.53; two reports). A higher risk of OASIS with median episiotomy use was shown in nulliparous (OR 5.11, 95% CI 3.23-8.08; two studies) as well as in parous (OR 89.4, 95% CI 11.8-677.1; one study) women. Lateral episiotomy was related to lower OASIS risk in nullipara (OR 0.59, 95% CI 0.49-0.70; single paper). Mediolateral episiotomy was linked to increased rates of postpartum haemorrhage (OR 1.82, 95% CI 1.16-2.86) and analgesia use (OR 2.10, 95% CI 1.39-3.17; two reports). Overall, the quality of evidence was rated as low to very low. Author's conclusions Mediolateral and median episiotomy in parous woman may increase the rate of OASIS at vacuum delivery, whereas lateral episiotomy in nulliparous women could be associated with a decreased risk of OASIS. The suboptimal quality of the available evidence necessitates high-quality well-designed randomised trials.