Influence of Borderline and Pathological Sperm Morphology on Pregnancy Outcomes following Intrauterine Insemination in Pregnant Women: A Retrospective Study.

Background: The prognostic value of borderline and pathological sperm morphology (SM) in infertility treatment remains unclear. This study aims to evaluate the potential impact of SM on clinical pregnancy outcomes following intrauterine insemination (IUI). Materials and Methods: This retrospective study reviewed IUI outcomes conducted between July 2012 to January 2017 at an infertility treatment center. Couples who underwent IUI and subsequently achieved a clinical pregnancy were included. Based on semen analysis according to the 6th edition of World Health Organization (WHO) guidelines, the couples were divided into two groups: borderline (4-13% normal forms) and pathological (<4% normal forms) SM. The study assessed the association between SM and pregnancy outcomes, specifically live birth and spontaneous abortion rates. Results: A total of 111 IUI cycles with confirmed clinical pregnancy were analyzed. Gestational complication rates were 8.3% in the borderline SM group and 17.3% in the pathological SM group, this difference was not statistically significant (P=0.255). However, live birth rates differed significantly between the two groups (borderline: 91.7%, pathological: 69.3%; P=0.009). Overall abortion rates were significantly higher in the Pathological SM group (borderline: 2.8%, pathological: 26.7%; P=0.001). First-trimester abortion rates were 5.6% and 18.7% in the borderline and pathological SM groups, respectively. Logistic regression analysis revealed that for every one-unit increase in the percentage of morphologically normal sperm, the odds of abortion decreased by a factor of 0.6 (P=0.017; OR=0.614; 95% CI: 0.412-0.916). Conclusion: Pathological SM is associated with a significantly higher risk of first-trimester abortion. Therefore, SM is highlighted as a potential predictor of IUI outcomes following clinical pregnancy. Subsequently, SM should be considered a critical factor in fertility assessments, and alternative treatment strategies may be more appropriate for couples with pathological SM undergoing infertility treatment.