Area under the curve for estradiol levels do not consistently reflect estradiol levels on the day of hCG administration in patients undergoing controlled ovarian hyperstimulation for IVF-ET.

PURPOSE: Most studies reported estradiol (E2) levels attained on day of hCG administration when investigating effect of E2 on IVF outcome. We studied whether a relationship exists between the area under the curve for E2 levels (AUC-E2) and E2 levels on hCG day during IVF-ET.
METHODS: Retrospectively, we analyzed data for 313 patients who completed one IVF-ET cycle each. Patients were sorted according to AUC-E2 levels. Then we compared between each patient's own AUC-E2 and the corresponding E2 level on hCG day for the same patient.
RESULTS: Although overall AUC-E2 correlated positively with E2 levels on hCG day, there was no consistent correlation between individual patients.
CONCLUSIONS: AUC-E2 reflects more accurately the amount of E2 produced by the follicles during controlled ovarian hyperstimulation. The absence of a uniform correlation between AUC-E2 and E2 on hCG day may result in different conclusions when studying outcomes of IVF treatment.