Endocrine Abstracts

Introduction: Polycystic ovary syndrome (PCOS) is a frequent cause of infertility. Its influence on the results of in vitro fertilization (IVF) is controversial, and generally not isolated from the effect of obesity. A relationship between the FSH receptor (FSHR) polymorphism Asn680Ser and the risk and phenotype of PCOS has been studied with conflicting results.

Objectives: To analyze the influence of obesity and PCOS on the gonadal axis and IVF results. To assess the influence of Asn680Ser on the risk of PCOS and IVF.

Material and Methods: Retrospective analysis of patients with PCOS by Rotterdam criteria with and without obesity and controls with tubal infertility, undergoing 1^st IVF after a short ovarian stimulation cycle with GnRH antagonist.

Results: Sample with 212 patients: 72 without obesity, with PCOS (group A); 75 without obesity or PCOS (B); 36 with obesity and PCOS (C); 29 with obesity, without PCOS (D). Mean age 33.5±3.7 years with homogeneous distribution between groups (P=0.207) and similar body mass index in the non-obese (A 23.8±2.9 vs B 23.3±2.7 kg/m2, P=0.203) and in the obese groups (C 33.9±3.0 vs D 33.1±2.1 kg/m2, P=0.305). The PCOS groups had: higher gonadotropins, LH/FSH ratio, testosterone, antral follicle count and anti-Mullerian hormone; lower luteal phase estradiol and progesterone (P<0.001 for all analyses). In the IVF results, the differences were more pronounced in the groups with vs without obesity, C and D (vs A and B) had: fewer mature oocytes (6.3±5.3 and 5.7±2.9 vs 9,1±6.8 and 6.7±5.2, P=0.035), less blastocysts (1.1±1.6 and 0.5±0.8 vs 1.7±2.3 and 1.6 ±2.2P=0.031) and lower embryo transfer rate (45.7 and 41.4 vs 68.8% and 69.3, P=0.007). In those who transferred embryos, the probability of pregnancy did not differ (P=0.197). In multivariate analysis, only obesity had an individual contribution to the transfer probability (P=0.001). The Asn680Serpolymorphism (analyzed in 113 cases) was present at a similar rate in patients with and without PCOS (65.7 vs54.4%, P=0.225) and was not associated with the likelihood of embryo transfer or pregnancy (P=0.452 and 0.174, respectively).

Discussion: Differences in IVF results were particularly related to obesity, suggesting that, although the hormonal changes associated with PCOS can be overcome by controlled ovarian stimulation, addressing obesity is essential for the success of IVF. In this population, Asn680Serwas not associated with the risk of PCOS or IVF outcomes.