Low serum estradiol concentrations after five days of controlled ovarian hyperstimulation for in vitro fertilization are associated with poor outcome.

OBJECTIVE: To evaluate the prognostic significance of low serum E2 concentrations in controlled ovarian hyperstimulation (COH) cycles for IVF.
DESIGN: Retrospective study.
SETTING: Assisted conception unit of a university hospital. PATIENT(S): One thousand four hundred and forty patients undergoing COH for IVF. INTERVENTION(S): COH, serum E2 measurement, ultrasonographic scanning of ovarian follicles, oocyte retrieval, and ET. MAIN OUTCOME MEASURE(S): Cancellation and pregnancy rates. RESULT(S): Patients were classified into four groups according to serum E2 levels on the sixth day of COH: group A (E2 level < 50 pg/mL [114 cycles]), group B (E2 level 51-100 pg/mL [189 cycles]), group C (E2 level 101-200 pg/mL [320 cycles]), and group D (E2 level >200 pg/mL [817 cycles]). Group A experienced the highest cancellation rates (65.1%) and lowest pregnancy rates (7.8%) despite requiring significantly more hMG ampules (47.8+/-1.7). The cancellation rate was higher (75.1%) and no pregnancy occurred in a subset of group A in whom COH was initiated with > or =3 ampules (225 IU) of gonadotropins. CONCLUSION(S): In COH cycles using luteal phase buserelin, low initial serum E2 concentrations are associated with poor outcome.