Geburtshilfe Frauenheilkd 2016; 76 - P256
DOI: 10.1055/s-0036-1593087

Pregnancy rates after slow release insemination: A report of two randomized controlled pilot studies and meta-analysis

M Franz 1, 2, J Ott 1, Y Gonen 3, JS Kruessel 4, L Kuessel 1, ML Trofaier 1, J Marschalek 1
  • 1Universitätsklinik für Frauenheilkunde und Geburtshilfe, Abteilung für gynäkologische Endokrinologie und Reproduktionsmedizin, Wien, Österreich
  • 2Praxis für gynäkologische Endokrinologie und Reproduktionsmedizin München Bogenhausen, München, Deutschland
  • 3Lin Medical Center, Haifa, Israel
  • 4Universität Düsseldorf, Gynäkologie und Geburtshilfe, Düsseldorf, Deutschland

Introduction: A modified application technique of intrauterine insemination is the slow release insemination (SRI), firstly described in 1992 by Muharib et al. who published higher pregnancy rates with SRI. This randomized cross-over study reported per cycle and cumulative pregnancy rates of 6.1% and 22% for standard bolus IUI, and 15.0% and 63.1% for SRI, respectively.

Study design: This study reports the results of two randomized cross-over pilot studies conducted in Germany and Israel between 2004 – 2007, and a meta-analysis of all eligible studies on SRI (n = 3).

Methods: Women with infertility aged between 20 to 40 years were randomly assigned to SRI or standard bolus IUI. The primary outcome parameter was serological pregnancy two weeks after insemination.

Results: Fifty treatment cycles (IUI: n = 25, SRI: n = 25) were performed in the German study, achieving four pregnancies (IUI: 4%, SRI: 12%, p > 0.05). Thirty-nine treatment cycles (IUI: n = 19, SRI: n = 20) were performed in the Israeli study, achieving six pregnancies (IUI: 10.5%, SRI: 20%; p > 0.05).

Both randomized controlled pilot studies could show a trend towards higher pregnancy rates by using the SRI-method.

A meta-analysis including these findings and the results of Muharib et al. revealed a relative risk for pregnancy after SRI of 2.64 (95% CI 1.04 – 6.74), p = 0.02) indicating a statistically significant advantage of SRI over conventional bolus IUI.

Conclusion: This study is the first since 1992 evaluating this novel approach to IUI lending support to the hypothesis that the pregnancy rate might be improved by using SRI rather than standard bolus IUI.