The effect of antibiotic treatment on pregnancy outcomes in patients with mild chronic endometritis undergoing in vitro fertilization.

OBJECTIVE

To study whether antibiotic treatment improves the pregnancy outcomes of frozen-thawed embryo transfer (FET) in infertile patients diagnosed with mild chronic endometritis (CE).

DESIGN

Propensity score-matched cohort study.

SUBJECTS: Women undergoing hysteroscopy with endometrial biopsy for previous failures of embryo transfer, history of recurrent pregnancy loss (RPL), abnormal uterine bleeding or suspicious of endometrial lesions (i.e., polyps, uterine adhesion) seen on transvaginal ultrasound. Mild CE was defined as 1-4 CD138+ endometrial stromal plasmacytes (ESPCs) per high-power field (HPF).

EXPOSURE: Patients with mild CE received 14 days of empirical antibiotic therapy (doxycycline, 100 mg, twice daily or levofloxacin lactate, 500 mg, once daily plus metronidazole, 200 mg, 3 times daily) or no treatment before single blastocyst FET.

MAIN OUTCOME MEASURES: The primary outcome was live birth. Secondary outcomes included other fertility outcomes such as clinical pregnancy and early pregnancy loss, as well as perinatal outcomes.

RESULTS

A total of 681 patients were diagnosed with mild CE, of whom 303 received antibiotics and 378 did not receive antibiotics. After propensity score matching, 303 pairs of patients were generated for comparative analysis. Live birth rate (LBR) between the antibiotics and untreated group was not significantly different (47.5% vs. 51.8%, relative risk [RR] 0.92, 95% confidence interval [CI] 0.78-1.08). All other reproductive, pregnancy and perinatal outcomes were also comparable. No significant differences were observed in fertility outcomes between the antibiotics and untreated cohorts across a range of cut-off values for the CD138 categories (from 1 ESPCs/HPF to ≤4 ESPCs/HPF), although severity of infection had no impact on the prognosis.

CONCLUSION

In this cohort study, we did not find an indication that antibiotic treatment improves pregnancy outcomes in patients with mild CE. Additionally, a higher CD138 category did not affect the prognosis.