Influence of male body mass index on semen analysis parameters and in vitro fertilization outcomes

Concurrent global increase of prevalence of obesity and male fertility implies link between overweight and obesity with male subfertility. This hypothesis is supported by numerous population-based epidemiological studies. Increase in body mass index (BMI) is associated with poor sperm quality in fertile, and more noticeable in infertile men. Nevertheless, some studies disprove damaging effect of BMI on semen quality. To examine the influence of men's BMI in infertile couples undergoing in vitro fertilization (IVF) on semen analysis parameters and IVF outcomes. Study encompassed all couples who underwent IVF at Gynecology and Obstetrics Clinic Narodni Front in Belgrade during 2018 and 2019. Exclusion criteria were azoospermia, conditions and diseases that could affect the semen analysis parameters (diabetes, malignant diseases treated with radiation and/or chemotherapy, trauma or surgery of the genital organs, mumps or undescended testicles in childhood). Evaluated semen analysis parameters included semen ejaculate volume, sperm pH, sperm count, sperm motility, and sperm morphology. IVF outcomes comprised total number of embryos, number and percentage of obtained good-quality embryos and clinical pregnancy rates. Based on BMI value, participants were divided into a group of underweight (Group 1), normally weight (Group 2), overweight (Group 3), and obese men (Group 4). After applying inclusion and exclusion criteria, 411 men (couples) were included in the analysis. The largest number of men were overweight, while the smallest belonged to the group of underweight participants. There are no significant differences in the semen analysis parameters between study groups. Correlation analysis shown weak and insignificant correlation between BMI and semen analysis parameters. The number and proportion of good quality embryos is significantly lower in overweight and obese study groups compared to normal weight and underweight groups (2.89, 2.91, 2.42, and 2.36, respectively, P = .041). The differences in other IVF outcomes: total number of embryos (3.61, 3.74, 3.21, and 3.37, respectively) and clinical pregnancy rates (41.26%, 43.09%, 42.78%, and 39.95%, respectively) between study groups were not significant (P > .05). BMI does not significantly affect semen analysis parameters, but a higher BMI is associated with a lower number and proportion of good quality embryos in IVF outcomes.