[Correlation between serum inhibin B level after treatment with gonadotropin releasing hormone agonist and outcome of in vitro fertilization-embryo transfer].

Objective: To evaluate the decreased level of serum inhibin B (INHB) treated by gonadotropin releasing hormone agonist (GNRH-a) in predicting ovarian response and pregnancy in in vitro fertilization-embryo transfer (IVF-ET).

Methods: The prospective study enrolled 124 women given by GnRH-a+ recombine follicle stimulating hormone (rFSH) + human chorionic gonadotrophin (hCG) long term stimulation protocol undergone their first cycle of IVF-ET treatment. The following predictive factors were collected and analyzed, such as age, basal level of follicle stimulating hormone (FSH), the ratio of FSH/ luteinizing hormone (LH), the concentration of INHB after down-regulation, total number of antral follicle count (AFC) and mean ovarian volume. Ovarian response was evaluated by the number of oocytes obtained. A multiple regression analysis and logistic regression model were used for all possible prognostic variables to evaluate the value of different hormones in predicting ovarian response and pregnancy after IVF-ET. Receiver operating characteristic (ROC) analysis was used to evaluate the level of INHB in predicting the number of oocytes obtained. The sensitivity and specificity were calculated at the discriminating cut-off point.

Results: The concentration of INHB after down-regulation showed a highly significant positive correlations with the number of oocytes obtained (r = 0.435, P < 0.01). The multiple regression analyses showed INHB was the most significant predictor of the number of retrieved oocytes, but INHB was not associated with IVF-ET outcome significantly (P > 0.05). ROC analyses showed INHB after down-regulation had the largest area under curve (AUC) 0.933 (95%CI: 0.878 - 0.988). When a threshold of 15 ng/L of INHB was established, 95.5% sensitivity and 50.0% specificity in ovarian response were observed.

Conclusions: The level of INHB was the best factor in predicting ovarian response in IVF-ET. Decreased level of INHB was the early sign of ovarian reserve function failure, however, useless in predicting IVF-ET outcome.