Endocrine Abstracts

Introduction: Evidence has suggested a relationship between female obesity and the outcomes of medically assisted reproduction techniques (MRT); however, the evidence regarding male obesity is still scarce and discordant.

Aim: Evaluate the influence of female and male obesity on the results of MRT.

Materials and methods: Retrospective analysis of 2159 couples, with and without obesity, submitted to the first treatment of medically assisted reproduction. Considering each individual of the couple, four groups were defined according to sex and body mass index (BMI) (non-obese group with BMI <30 kg/m² and obese group with BMI ≥ 30 kg/m²).

Results: Among female individuals, 235 were obese (10.9%). Median age was similar between groups with and without obesity (35 years (31-37) vs 34 years (31-37), P=0.541). Ovarian stimulation was mostly performed with a short cycle with an antagonist in both groups (75.1% vs 68.6%, P=0.674) and in vitro fertilization was the most frequent technique in both groups (60.9% vs 66.9%, P=0.086). The obese group had a lower number of mature oocytes (4 (2-7) vs 5 (2-8), P=0.015) and of fertilized oocytes (2 (0-4) vs 2 (0-5), P=0.026). The fresh embryo transfer rate was similar between groups (50.2% vs 54.8%, P=0.119), as well as the probability of pregnancy (31.4% vs 38.3%, P=0.103). Among male individuals, 336 were obese (15.6%) and median age was similar between groups (36 years (33-39) vs 35 years (32-39), P=0.357). No differences were observed in the several parameters evaluated on the semen analysis or in the results of MRT, namely in the number of embryos obtained, transfer rate or pregnancy.

Conclusions: In this population, female obesity influenced the number of mature and fertilized oocytes. We believe that the lack of statistically significant difference in the rate of freshly transferred embryos between the female groups is related to the lack of fresh transfer in several patients due to the risk of Ovarian Hyperstimulation Syndrome. The analysis of frozen embryo transfer data would have been important for a better characterization of the embryo transfer rate in these groups. In this study, there does not seem to be a relationship between male obesity and sperm analysis parameters or the success of MRT.