Coordination of early antral follicles by luteal estradiol administration provides a basis for alternative controlled XXXX regimens.

@entity1 @entity43
OBJECTIVE: To investigate whether luteal E(2) administration reduces size discrepancies of early antral follicles. DESIGN: Prospective, crossover study. SETTING: ART unit, Clamart, France. @entity1 (S): Sixty @entity1 and 120 cycles. INTERVENTION(S): On cycle day 3 (baseline day 3), all @entity1 underwent measurements of early antral follicles by ultrasound and serum FSH and ovarian hormones. From day 20 until the next cycle day 2, 30 of them received oral 17beta-E(2), whereas the remaining @entity1 served as controls. The day after E(2) discontinuation (E(2) day 3) or on subsequent cycle day 3 (control day 3), @entity1 were reevaluated as on baseline day 3. MAIN OUTCOME MEASURE(S): Magnitude of follicular size discrepancies. RESULT(S): Follicular size discrepancies and follicular diameters were significantly attenuated on E(2) day 3 (3.7 +/- 0.5 mm) as compared with baseline day 3 (4.9 +/- 1.0 mm), but not in controls (5.0 +/- 0.8 vs. 4.9 +/- 0.8 mm). FSH (4.3 +/- 1.9 vs. 7.3 +/- 3.3 mIU/mL) and inhibin B (34 +/- 28 vs. 71 +/- 32 pg/mL) levels were consistently lower on E(2) day 3 than on baseline day 3 but remained unchanged in controls. CONCLUSION(S): Luteal E(2) administration reduces the size and improves the homogeneity of early antral follicles on day 3. This approach may be instrumental in synchronizing follicular development during controlled @entity43 .
