Stepwise regression analysis to study male and female factors impacting onpregnancy rate in an intrauterine insemination programme

The aim of this study was to evaluate the impact of male and female factors on the pregnancy rate in an intrauterine insemination (IUI) programme. Dat a on 522 cycles were retrospectively studied. All patients 39 years or youn ger were included in the study where data were available on male and female diagnosis, as well as on ovulation induction methodology. Regression analy sis was possible on 495 cycles to study different factors affecting the pre gnancy rate per treatment cycle. Logistic regression identified variables w hich were related to outcome and were subsequently incorporated into a stat istical model. The number of follicles was found to have a linear associati on with the risk ratio (chance) of pregnancy. The age of the woman was also found to have a linear (negative) association with pregnancy. The percenta ge motility and percentage normal morphology (by strict criteria) of sperma tozoa in the fresh ejaculate were the male factors that significantly and i ndependently predicted the outcome. Percentage motility 250 was associated with a risk ratio of pregnancy of 2.95 compared to percentage motility < 50 . Percentage normal sperm morphology > 14% was associated with a risk ratio of pregnancy of 1.8 compared to percentage normal morphology less than or equal to 14%. Female patients with idiopathic infertility were divided into three groups according to normal sperm morphology. The pregnancy rate per cycle was 2.63% (1/38) for the P (poor) pattern group (0-4 % normal forms), 11.4 % (17/119) for the G (good) pattern group (5-14%), and 24% (18/75) fo r the N (normal) pattern group (> 14% normal forms). A female diagnosis of endometriosis or tubal factor impacted negatively on the probability of pre gnancy (risk ratio of 0.17), compared with other female diagnoses. Male and female factors contribute to pregnancy outcome, but the clinician can infl uence prognosis by increasing the number of follicles, especially in severe male factor cases.