Does antibiotic use prevent wound complications in episiotomy, second-degree tear?

The use of prophylactic antibiotics shows no significant impact on overall wound complication but leads to a significant risk reduction in clinically relevant wound complications among women with episiotomies and second-degree tears, reports a study.

“This finding supports the use of prophylactic antibiotics in routine clinical practice after a second-degree tear or episiotomy,” the investigators said.

A single-centre, double-blind, placebo-controlled randomized trial was conducted in a university hospital in Denmark and enrolled 442 women with episiotomies or second-degree tears between March and December 2023. Participants were randomized to either three doses of amoxicillin (500 mg) with clavulanic acid (125 mg) or placebo starting within 6 h postpartum and repeated at 8-h intervals.

The investigators conducted follow-up 4 to 14 days postpartum. All participants, physicians, and the steering committee were blinded. Wound complications served as the primary outcome, while clinically relevant wound complications were secondary.

Of the participants, 433 completed follow-up and were included in the primary analysis. No significant difference was seen in overall wound complications between the antibiotic and placebo groups (22 percent vs 29 percent; p=0.10), with a risk difference of ‒7.2 percent (95 percent confidence interval [CI], ‒15.4 to 0.8) and a relative risk of 0.75 (95 percent CI, 0.54‒1.04). [BMJ 2025;391:e084312]

However, significantly fewer clinically relevant wound complications occurred in the antibiotic group (9 percent vs 17 percent; p=0.01), with a risk difference of ‒8.0 percent (95 percent CI, ‒14.3 to ‒1.8) and a relative risk of 0.52 (95 percent CI, 0.31‒0.88). The number needed to treat was 12 (95 percent CI, 7‒56) for clinically relevant wound complications.

For exploratory outcomes, women who received prophylactic antibiotics reported better self-assessed health, received fewer additional antibiotic treatments, and had smaller average wound dehiscence among those with dehiscence. Additionally, serious adverse reactions did not occur.

“Although no significant effect was seen for overall wound complications, prophylactic antibiotics significantly reduced the risk of clinically relevant wound complications in women with episiotomies and second-degree tears and should be considered in postpartum care,” the investigators said.

Caution

While exploratory outcomes showed improved wellbeing in the treatment group, these should be interpreted with caution due to a lack of prespecification in trial registration and statistical analysis plan and lack of multiple testing, according to the investigators.

“Unlike another study by Tandon and Dalal we found no difference in pain, possibly due to its high overall prevalence,” they added. [J Obstet Gynaecol India 2018;68:294-299]

In a subgroup analysis, a significant effect was also observed in low-risk groups. On the other hand, results of the ANODE trial showed benefits to high-risk women, which prompted the WHO to recommend the use of antibiotics for this group. [www.who.int/publications/i/item/9789240027992]

“Generalizability may be limited and selection bias introduced because of the single-centre design, inclusion restricted to Danish-speaking women, and lack of ethnicity data,” the investigators said.

“Exclusion of women receiving intrapartum antibiotics helped isolate the prophylactic effect but may reduce generalizability, as could differences in pathogens, resistance patterns, and obstetric practices such as episiotomy and instrumental delivery,” they added.