Physician-authored summaries and commentary on the most important medical research, provided by the NEJM Group, a division of the Massachusetts Medical Society.
© Massachusetts Medical SocietySeptember 2024
Risk for obstetric anal sphincter injury was halved with routine lateral episiotomy.
Episiotomy in assisted vaginal delivery is controversial, with marked variation in practice patterns (NEJM JW Womens Health Feb 2015 and JAMA 2015; 313: 197-199). Evidence suggests there might be a role for lateral episiotomy for nulliparous patients requiring vacuum-assisted delivery. In this study, Swedish researchers identified 717 nulliparous women with a single live cephalic fetus at 34 weeks or more gestation who required vacuum assistance for delivery. They were randomised to receive standardised lateral episiotomy (beginning 1 to 3 cm from the posterior fourchette, at a 60° angle from the midline, and 4 cm long) or to no episiotomy.
Key results were as follows:
- rate of obstetric anal sphincter injury, the primary outcome, was 13% in the no-episiotomy (control) group compared with 6% in the episiotomy group, with similar findings in both intention-to-treat and per-protocol analyses
- there were no differences in postpartum haemorrhage, perineal pain, birth experience, length of hospitalisation or neonatal outcomes between groups, although both wound infections (9% vs 5%) and wound dehiscence (9% vs 3%) were more common in the episiotomy arm.
Comment: A restrictive approach to episiotomy has become more common in recent years. At my institution and others (based on informal discussions), obstetricians use clinical judgement and individualise these decisions. Given the tradeoffs illustrated in this randomised trial, that approach seems reasonable.
Although these findings support considering routine lateral episiotomy for nulliparous patients who require vacuum-assisted delivery, note that episiotomy in other groups (e.g. parous women requiring vacuum delivery) has been associated with increased risk of obstetric anal sphincter injury and should not be routinely recommended.
Marie Claire O’Dwyer, MB BCh BAO, MPH, Clinical Assistant Professor in Family Medicine, University of Michigan Medical School, Ann Arbor, USA.
Bergendahl S, et al. Lateral episiotomy or no episiotomy in vacuum assisted delivery in nulliparous women (EVA): multicentre, open label, randomised controlled trial. BMJ 2024; 385: e079014.
This summary is taken from the following Journal Watch title: Women’s Health.