Antibiotic use for chronic endometritis poses risk of miscarriage after ART

The use of antibiotic therapy to resolve chronic endometritis (CE) can put women undergoing assisted reproductive treatment (ART) at heightened risk of pregnancy loss, according to a study.

The study included 8,300 infertile women who underwent a routine hysteroscopy and an in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment. Of these, 338 women had chronic endometritis and received antibiotic therapy (cured CE group), while 7,962 had no such condition (control).

A total of 7,218 patients women underwent embryo transfer, with 330 in the cured CE group and 6,888 in the control group. The primary outcome of spontaneous abortion occurred more frequently in the cured CE group than in the control group (11.8 percent vs 9.2 percent; crude odds ratio [OR], 1.32, 95 percent confidence interval [CI], 0.94–1.86).

Multivariable logistic regression analysis confirmed that antibiotic-cured CE increased the odds of spontaneous abortion by almost 50 percent (adjusted OR, 1.49, 95 percent CI, 1.01–2.19).

The live birth rate was also lower in the cured CE group (43.9 percent vs 50.5 percent; crude OR, 0.77, 0.62, 0.96; adjusted OR, 0.73, 95 percent CI, 0.59–0.92). However, there was no significant between-group difference in the incidence of clinical pregnancy (56.1 percent vs 60.0 percent; crude OR, 0.85, 95 percent CI, 0.68–1.06; adjusted OR, 0.83, 95 percent CI, 0.66–1.03).

Sensitivity analyses stratified by initial fresh- or frozen-thawed embryo transfer cycles yielded similar findings.

The study might be limited by a potential confounding bias.