The evaluation of the sperm migration test as a predictor for success with intrauterine insemination

Objective-The objective of this study was to prospectively evaluate the sperm migration test (SMT) as a discriminator in couples undergoing intrauterine insemination (IUI). Patients and Methods-261 couples underwent 797 IUI treatment cycles involving gonadotropin stimulation in the three year period. All had a diagnosis of unexplained infertility. All male partners underwent a repeat standard seminal analysis and SMT prior to the female partner undergoing controlled ovarian stimulation. Results-Despite apparently normal seminal analyses before referral, in 22 samples the sperm concentration, motility or morphology were abnormal (WHO criteria). Of these, 20 couples underwent 109 cycles and achieved 2 pregnancies giving a pregnancy rate of 1.8% per cycle and a cumulative pregnancy rate of 10% per couple. From the remaining couples with normal seminal analyses, 71 had an SMT 5 million/mL. The suboptimal SMT group underwent 276 cycles (3.89 cycles per couple) and achieved 18 pregnancies giving a pregnancy rate of 6.5% per cycle and a cumulative pregnancy rate of 25.4%. The normal SMT group underwent 412 cycles (2.45 cycles per couple) and achieved 60 pregnancies giving a pregnancy rate of 14.6% per cycle and a cumulative pregnancy rate of 35.7%. Conclusions-We confirm that abnormal seminal analysis leads to poor pregnancy rates with IUI. However, an SMT <5 million/mL despite normal seminal analysis (WHO criteria) also leads to significantly worse pregnancy rates. We would recommend that prior to IUI, couples are screened using the SMT.