An Analysis of pre and post-Processing Semen Parameters at The Time of Intrauterine Insemination; and The Confounding Effects of Total Motile Sperm Counts on Pregnancy Outcome: A Prospective Cohort Study

This study aims to determine whether pre or post-processing semen parameters obtained during intrauterineinsemination (IUI) predict pregnancy when controlling for confounding effects. A prospective cohort study of 2231 semen analyses was conducted at McGill University ofIVF center. Any couples who underwent IUI with partner sperm, over a 2.5-year period, were included. Controlledovarian stimulation was done with Clomiphene Citrate, Letrozole, or Gonadotropins. Statistical analysis was performedusing t tests, two types of stepwise logistic regression, and stepwise discriminant analysis. A comparison ofpre and post-processing semen parameters was undertaken to determine the probability of pregnancy. There were significant differences between pregnant and non-pregnant women in post-processing concentration(P=0.043), post-processing total motile sperm count (TMSC) (P=0.049), and post-linearity (P=0.012). However,when variable out-of-the-equation logistic regression or discriminant analysis, which controls for confounding effectsbetween variables, were used, the findings were no longer significant. It was statistically proven that when a variablein the equation logistic regression was employed, post-processing concentration (P=0.005) and post-processingTMSC (P=0.009) remained reliable predictors of pregnancy. Two of three prediction models suggested that TMSC’s relationship with pregnancy is due to confoundingfactors. One model maintained the validity of the TMSC. While TMSC has always been studied as an importantpredictor of insemination pregnancies, this finding may be due to confounding effects between semen parameters andtherefore requires further investigation as to this relationship.