TMNSC: a new predictor of pregnancy after IUI

Introduction: Processed total motile sperm count (pTMSC) is known to affect the outcome of intrauterine insemination (IUI) and it has been suggested that IUI should be considered only when pTMSC is >10 million. We designed an observational prospective study to determine the suitability of the total number of motile sperm with normal morphology (pTMNSC) as predictor of pregnancy after IUI. Materials and methods: From January 1999 to December 2002, 256 infertile couples underwent 809 consecutive inseminations. The clinical and semen parameters were prospectively recorded on a computerized database. pTMNSC was calculated by multiplying the volume of the processed sample, the sperm concentration, the percentage of motile sperm and the percentage of sperm with normal morphology. Couples were considered to be candidates for treatment by IUI if the woman had at least one open fallopian tube (ascertained either by hystero-salpingo- graphy or by laparoscopy). Pregnancy was diagnosed by determination of HCG serum concentrations 14±16 days after IUI and detection of the gestational sac 4±5 weeks after IUI by ultrasound examination. Logistic regression was carried out to de®ne the factors that have the strongest impact on the likelihood of achieving a pregnancy. Results: The total number of pregnancies was 74, resulting in a per cycle pregnancy rate of 9.1% and a couple pregnancy rate of 28.9%. Interestingly, 475 IUI cycles were performed in couples with pTMSC <10 million resulting in a per cycle pregnancy rate of 10.1%. In our cohort of infertile couples, pTMNSC ranged between 10 Q 103 and 343 Q 106, with a median value of 1 230 000. On logistic regression analysis pTMNSC was independently associated with conception after IUI (P = 0.027). The value of pTMNSC as a prognostic factor in IUI cycles was evaluated controlling for the following factors: woman's age, woman's body mass index, infertility diagnoses, and duration of infertility. On logistic regression analysis female age was independently associated with conception after IUI (P = 0.038). Conclusions: In IUI cycles pTMNSC and female age independently predict the likelihood of achieving a pregnancy.