The predictive value of ovarian reserve tests for spontaneous pregnancy in subfertile ovulatory women

BACKGROUND: The predictive value of ovarian reserve tests (ORTs) for spontaneous pregnancy is unclear. Our study aimed to determine whether ORTs have added value to previously identified prognostic factors for spontaneous pregnancy in subfertile ovulatory couples. METHODS: A prospective cohort study was performed on 474 subfertile ovulatory couples in two hospitals in Groningen, The Netherlands. The ORTs performed were: antral follicle count (AFC), follicle-stimulating hormone (FSH), inhibin B (basal levels and after stimulation with clomiphene citrate) and the clomiphene citrate challenge test. For each couple, the probability of spontaneous pregnancy was retrospectively calculated using the validated Hunault prediction model which includes the main known prognostic factors for spontaneous pregnancy. Outcome measure was time to spontaneous pregnancy resulting in a live birth. RESULTS: When added to the Hunault model, only basal FSH and AFC significantly improved the prediction of spontaneous pregnancy (P-values of 0.05 and 0.04). Absolute changes in predicted probabilities after adding basal FSH or AFC were small: the predicted probability of spontaneous pregnancy shifted >= 10% in only 3.8% and 7.9% of the couples, respectively. CONCLUSIONS: Although basal FSH and AFC significantly improved the validated prediction model for spontaneous pregnancy, the clinical relevance of this finding is limited. We recommend that none of the ORTs studied should be used routinely in the subfertility evaluation of ovulatory couples to predict spontaneous pregnancy chances.