To compare the prevalence of chronic endometritis (CE) in women with hydrosalpinx undergoing in vitro fertilization (IVF), to a control group without hydrosalpinx.

A bicentric historical prospective case-control study, between June 2017 and December 2021.

Angers and Montreal university hospitals.

In the Hydrosalpinx (H) group, we included all women undergoing IVF for various indications, and who were diagnosed with a hydrosalpinx before or during the cycle. In the control (C) group, we included women without hydrosalpinx, undergoing IVF for male factor infertility, or following bilateral tubal ligation.

A laparoscopy was scheduled for the removal of the hydrosalpinx, and an endometrial biopsy was performed concomitantly to rule out CE. In the C group, an endometrial biopsy was performed in the clinic. CE diagnosis was confirmed using immunohistochemistry.

Our primary endpoint was the rate of positive biopsies for CE. Ninety-four patients were included, 62 in the H group and 32 in the C group. Mean age was 32.1 ± 5.1 years. The prevalence of CE was significantly higher in the H group compared to the C group (41.9% (26/62) vs 15.6% (5/32) (p = .01)). Multivariate analysis showed that the presence of hydrosalpinx was an independent risk factor of CE (aOR = 3.93 (1.31–11.81)), whether the hydrosalpinx was unilateral (aOR = 4.39 (1.32–14.61)) or bilateral (aOR = 3.52 (1.01–11.99)).

There is a significant increase in the prevalence of CE in women with hydrosalpinx undergoing IVF, whether the hydrosalpinx was unilateral or bilateral.