Préservation de la fertilité dans l’endométriose : étude de 52 cas en Aquitaine

Objective: to find predictive factors of vitrified oocytes number in patients with endometriosis who benefit from fertility preservation by oocyte vitrification. Design: retrospective, unicentric, observational cohort study between January 2000 and October 2019. Setting: Bordeaux University Hospital. Patients: fifty-two patients who underwent in total 101 Controlled Ovarian Stimulation (COS) cycles. Intervention: None. Main outcome: number of vitrified oocytes per cycle. Results: mean age of patients was 31.5 ± 4.3 years [20-39]. A predictive analysis of vitrified oocytes number was performed after exclusion of 11 cycles stopped during stimulation. The remaining 90 cycles were divided into 3 categories: low response ( 7 oocytes). AMH was highly predictive of this classification with mean levels of 1.06  0.7 ng/ml, 1.97  1.59 ng/ml and 2.81  2.04 ng/ml respectively for the three groups low, intermediate and satisfactory response (p <0.0001). AFC was also a good predictive factor with mean values of 8.25  2.82, 10.4  4.54 and 13.88  6.54 in these groups (p=0.001). The total dose of gonadotropins was also strongly correlated with this classification, with decreasing values in doses (4739  1749 IU/L, 3317  884 IU/L and 3265  1177 IU/L respectively for the three groups (p <0.001)). After multivariate analysis, only two variables were selected as independent predictive factors of vitrified oocytes number: AMH (p <0.0001, R=+0.404) and the total dose of gonadotropins used (p=0.001, R=-0.318). In contrast, endometriosis phenotype, ovarian involvement at the time of stimulation and history of ovarian surgery were not significantly correlated with the number of vitrified oocytes. Conclusion: in our study, results of oocyte vitrification in patients with endometriosis do not seem to be affected by medical history or endometriotic phenotype, but rather by low ovarian reserve, as assessed by AMH levels and insufficient hormonal stimulation response (as evidenced by increased doses of gonadotropins).