Effect of uterine peristalsis at the time of embryo transfer on the outcomes of IVF cycles: a prospective cohort study.

Abstract

Background: It has recently been discovered that one of the key elements influencing endometrial receptivity is uterine peristalsis. This was a prospective cohort study aiming to assess uterine peristalsis at the time of embryo transfer in women undergoing IVF.

Methods: Uterine peristaltic waves were assessed using transvaginal ultrasound by recording a 3-minute video to determine the frequency and the direction of peristalsis. Primary outcome was clinical pregnancy while secondary outcomes were biochemical pregnancy, miscarriage, ectopic pregnancy and live birth. Outcomes were compared in women who had no peristalsis (Absent group), had one or two waves per minute (< 3 Group), or those who had 3 or more waves per minute (≥ 3 Group).

Results: Between August 2023 and January 2025, 127 women were included in this study, of whom 76 (59.8%) were fresh cycles and 51 (40.2%) were frozen cycles. The median number of peristaltic waves was one per minute. Peristalsis was absent in 34 women, < 3 in 72 women and ≥ 3 in 21 women. There was no statistically significant difference in pregnancy rate between the three groups (26.1% in absent group, 36.1% in < 3 group, and 33.3% in ≥ 3 group). The direction was cervico-fundal in 62 women, fundo-cervical in 5 women, and random in 26 women, with pregnancy rates 22%, 0% and 11%, respectively, with no statistically significant difference.

Conclusion: We did not find a significant effect of the number or the direction of uterine peristalsis on any of the clinical outcomes of IVF. Therefore, we do not recommend its routine assessment before embryo transfer until further evidence is available.

Trial registration: The study protocol was registered on 14 September 2023 at ClinicalTrials.gov (Registration number NCT06036459).