Prophylactic antibiotics for the prevention of infection following operative vaginal delivery (ANODE): study protocol for a randomised controlled trial.

BACKGROUND: Sepsis is one of the most important causes of maternal death and severe morbidity worldwide. Studies conducted both in the UK and US have documented an additional risk associated with operative vaginal delivery. However, a Cochrane review, updated in 2017, identified only one small trial of prophylactic antibiotics following operative vaginal delivery, which included a total of 393 women. Given the small size of that trial, it recommended that further robust evidence is needed. Operative vaginal delivery rates vary worldwide, but typically 5-10% of women have operative vaginal births. A conservative estimated incidence of maternal infection following operative vaginal delivery is 4%, based on the one previous trial. There is, therefore, considerable scope for direct patient benefit from an effective preventive strategy.

METHODS/DESIGN: This protocol describes a multicentre, randomised, blinded, placebo-controlled trial aiming to recruit 3424 participants from over 20 hospital sites in the UK. Women who have undergone an operative vaginal delivery at 36+0 weeks or greater gestation with no indication for ongoing antibiotics in the postpartum period and no contra-indications to prophylactic co-amoxiclav, will be randomised to receive a single intravenous dose of co-amoxiclav or placebo. The primary outcome will be confirmed or suspected maternal infection within 6 weeks of delivery, as defined by one of (a) a new prescription of antibiotics for presumed perineal wound-related infection, endometritis or uterine infection, urinary tract infection with systemic features or other systemic infection, (b) systemic infection confirmed with a culture or (c) endometritis as defined by the US Centers for Disease Control and Prevention. Outcome information will be collected by a single telephone interview and questionnaire, with clinical data collected from medical records or the hospital laboratory if necessary, at 6 weeks post-delivery.

DISCUSSION: This randomised trial will investigate whether a prophylactic dose of antibiotic following operative vaginal delivery can reduce the incidence of infection and sepsis. If shown to be effective, this could lead to a change in recommended practice and the prevention of infection. Conversely, if there is no significant difference between the two arms, then this could contribute to a reduction in antibiotic use and improved antimicrobial stewardship.

TRIAL REGISTRATION: ISRCTN11166984 . Registered on 23 September 2015.