Pathological semen parameters according to WHO and Austrian IVF funds criteria and their association with pregnancy outcomes in assisted reproduction

BACKGROUND: Male factors account for around half of all cases of infertility. The prognostic relevance of abnormal semen parameters for obstetric outcomes following assisted reproductive technology (ART) is unclear. METHODS: This retrospective analysis included 428 participants enrolled in the prospective Austrian registry (AROS) between January 2022 and August 2025. Male-factor infertility was defined according to the reference values of the World Health Organization (WHO) 6th edition and the criteria of the Austrian in vitro fertilization (IVF) funds. Associations between infertility factors and pregnancy complications, mode of delivery, and preterm birth were assessed using logistic and ordinal logistic regression, as appropriate. RESULTS: Male-factor infertility was documented in 254 cases, while female factors were documented in 206 cases, with some overlap between the two. Pregnancy complications occurred in 63.8% of cases. The caesarean section rate was 58.6%, including 20.8% secondary caesarean sections. Preterm birth occurred in more than 25% of pregnancies. Multiple pregnancy (27.3%) was strongly associated with pregnancy complications (p < 0.001), an adverse mode of delivery (p = 0.004), and preterm birth (p < 0.001). Male-factor infertility, as defined by the IVF funds criteria, showed a trend towards reduced odds of pregnancy complications (OR: 0.45; 95% CI: 0.20-1.02; p = 0.056). CONCLUSION: Male factor as defined by the Austrian IVF funds is a favorable prognostic parameter, whereas multiple pregnancy has the worst impact on pregnancy outcomes.