Ovarian volume and antral follicle count for the prediction of low and hyper responders with in vitro fertilization

Background: The current study was designed to compare antral follicle count ( AFC) and basal ovarian volume ( BOV), the exogenous FSH ovarian reserve test ( EFORT) and the clomiphene citrate challenge test ( CCCT), with respect to their ability to predict poor and hyper responders. Methods: One hundred and ten regularly menstruating patients, aged 18 - 39 years, participated in this prospective study, randomized, by a computer designed 4- blocks system study into two groups. Fifty six patients underwent a CCCT, and 54 patients underwent an EFORT. All patients underwent a transvaginal sonography to measure the basal ovarian volume and count of basal antral follicle. In all patients, the test was followed by a standard IVF treatment. The result of ovarian hyperstimulation during IVF treatment, expressed by the total number of follicles, was used as gold standard. Results: The best prediction of ovarian reserve ( Y) was seen in a multiple regression prediction model that included, AFC, Inhibin B- increment in the EFORT and BOV simultaneously ( Y = - 3.161 + 0.805 x AFC ( 0.258- 1.352) + 0.034 x Inh. B- incr. ( 0.007- 0.601) + 0.511 BOV ( 0.480- 0.974) ( r = 0.848, p < 0.001). Univariate logistic regression showed that the best predictors for poor response were the CCCT ( ROC- AUC = 0.87), the bFSH ( ROC- AUC = 0.83) and the AFC ( ROC- AUC = 0.83). Multiple logistic regression analysis did not produce a better model in terms of improving the prediction of poor response. For hyper response, univariate logistic regression showed that the best predictors were AFC ( ROC- AUC = 0.92) and the inhibin B- increment in the EFORT ( ROCAUC = 0.92), but AFC had better test characteristics, namely a sensitivity of 82% and a specificity 89%. Multiple logistic regression analysis did not produce a better model in terms of predicting hyper response. Conclusion: In conclusion AFC performs well as a test for ovarian response being superior or at least similar to complex expensive and time consuming endocrine tests. It is therefore likely to be the test for general practise.