Techniques used for IUI: is it time for a change?

STUDY QUESTION: Are the guidelines for the technical aspects of IUI (WHO, 2010) still in accordance with the current literature? SUMMARY ANSWER: In general, the laboratory guidelines of the World Health Organization (WHO) are a suitable protocol, although the evidence is not always conclusive and some changes are advisable. WHAT IS KNOWN ALREADY: Lack of standardization of the technical procedures required for IUI might result in inter-laboratory variation in pregnancy rates. Most centers still use their own materials and methods even though some guidelines are available. STUDY DESIGN, SIZE, DURATION: A structural review focusing on the association between pregnancy rates and the procedures of semen collection (e.g. ejaculatory abstinence, collection place), semen processing (e.g. preparation method, temperature during centrifugation/storage), insemination (e.g. timing of IUI, bed rest after IUI) and the equipment used. PARTICIPANTS/MATERIALS, SETTING, METHODS: A literature search was performed in Medline and the Cochrane library. When no adequate studies of the impact of a parameter on pregnancy results were found, its association with sperm parameters was reviewed. MAIN RESULTS AND THE ROLE OF CHANCE: For most variables, the literature review revealed a low level of evidence, a limited number of studies and/or an inadequate outcome measure. Moreover, the comparison of procedures (i.e. semen preparation technique, time interval between semen, collection, processing and IUI) revealed no consensus about their results. It was not possible to develop an evidence-based, optimal IUI treatment protocol. LIMITATIONS, REASONS FOR CAUTION: The included studies exhibited a lack of standardization in inclusion criteria and methods used. WIDER IMPLICATIONS OF THE FINDINGS: This review emphasizes the need for more knowledge about and standardization of assisted reproduction technologies. Our literature search indicates that some of the recommendations in the laboratory guidelines could be adapted to improve standardization, comfort, quality control and to cut costs. STUDY FUNDING/COMPETING INTEREST(S): The Dutch Foundation for Quality Assessment in Medical Laboratories (SKML), Nijmegen, The Netherlands. S.K. and W.N. have no conflicts of interest to disclose. C.B. and A.W. are members of the board of the SKML. With a grant from SKML, L.L. was paid for her time to perform the research and write the publication. D.B. received grants from Merck Serono, Ferring and MSD, outside the submitted work. REGISTRATION NUMBER: N/A