The correlation of the degree of abnormal sperm morphology using strict criteria and pregnancy rates following intrauterine insemination (IUI)

To determine the effect of extremely low sperm morphology on pregnancy rates following intrauterine insemination (IUI) where all other semen parameters were normal. Retrospective review of all IUI cycles over a two-year period on infertile women age ≤ 35 where all parameters, but morphology had to be normal. The data were evaluated according to seven levels of percentage of normal morphology (NM): 0, 1, 2, 3, 4, 5, and ≥ 6%. The percent live delivery was 9.5, 16.7, 8.8, 16.1, 11.4, 12.3, and 10.9%. Morphology of 0% or 1% did not seem to impair pregnancy rates following IUI. More studies are needed but should include determining the confounding effect of the type of morphologic abnormality.