Pregnancy rates after slow-release insemination (SRI) and standard bolus intrauterine insemination (IUI) \u2013 A multicentre randomised, controlled trial

Julian Marschalek,Andreas Obruca,Elisabeth Vytiska-Binsdorfer,Maximilian Franz,Maarten Van Santen,Johannes Ott,Christian Egarter,Jackie Campbell,Philip Harris,Bernd Lesoine

doi:10.1038/s41598-020-64164-4

Abstract

This multicentre, randomised, controlled cross-over trial was designed to investigate the effect of intra-uterine slow-release insemination (SRI) on pregnancy rates in women with confirmed infertility or the need for semen donation who were eligible for standard bolus intra-uterine insemination (IUI). Data for a total of 182 women were analysed after randomisation to receive IUI (n = 96) or SRI (n = 86) first. The primary outcome was serological pregnancy defined by a positive beta human chorionic gonadotropin test, two weeks after insemination. Patients who did not conceive after the first cycle switched to the alternative technique for the second cycle: 44 women switched to IUI and 58 switched to SRI. In total, there were 284 treatment cycles (IUI: n = 140; SRI: n = 144). Pregnancy rates following SRI and IUI were 13.2% and 10.0%, respectively, which was not statistically significant (p = 0.202). A statistically significant difference in pregnancy rates for SRI versus IUI was detected in women aged under 35 years. In this subgroup, the pregnancy rate with SRI was 17% compared to 7% with IUI (relative risk 2.33; p = 0.032) across both cycles. These results support the hypothesis that the pregnancy rate might be improved with SRI compared to standard bolus IUI, especially in women aged under 35 years.

Highlights

10–15% of couples of reproductive age are affected by infertility[1]
The hypothesis is that the presence of a higher sperm density in the fallopian tubes at the time of ovulation is more likely to result in pregnancy; available evidence suggests that there is no clear benefit for ITI/fallopian tube sperm perfusion (FSP) over IUI18–20
The EVIE device did not fully actuate in one patient assigned to the slow release insemination (SRI) group: she received a bolus at the end of the 4-hour administration period and her data were excluded from the analysis

Summary

Introduction

10–15% of couples of reproductive age are affected by infertility[1]. Following diagnosis of infertility, and evaluation of its causes, couples can be provided with information about their likelihood of achieving a spontaneous pregnancy, and their chance of pregnancy after different treatment options. A large retrospective cohort study, covering more than 15,000 IUI-cycles, reported a mean pregnancy rate of 5.6% per cycle, and cumulative ongoing pregnancy rates after the third, seventh and ninth cycles of 18%, 30% and 41%, respectively[7,8] These data clearly show the importance of developing new strategies for improving pregnancy rates after IUI. The hypothesis is that the presence of a higher sperm density in the fallopian tubes at the time of ovulation is more likely to result in pregnancy; available evidence suggests that there is no clear benefit for ITI/FSP over IUI18–20. Another modified IUI application technique is slow release insemination (SRI), which was first described in 199221. The present, larger, multicentre trial was performed to clarify the effect of intra-uterine SRI on pregnancy rates in women designated for standard bolus IUI

Methods

Results

Discussion

Conclusion