Early follicle development during the luteal-follicular transition affects the predictability of serum follicle-stimulating hormone but not antimüllerian hormone levels on cycle day 3.

OBJECTIVE: To verify whether the presence of an overdeveloped antral follicle modifies the expected relationship between serum antimüllerian hormone (AMH), estradiol, or follicle-stimulating hormone (FSH) levels and antral follicle count on cycle day 3. DESIGN: Prospective study. SETTING: Teaching hospital, France. PATIENT(S): Two hundred seventy-seven normo-ovulating women. INTERVENTION(S): Serum AMH, estradiol, and FSH levels and the number and size of antral follicles (3 to 12 mm) were measured on cycle day 3. Two groups were set according to the presence ("large" group) or absence ("small" group) of at least one follicle measuring >7 mm. MAIN OUTCOME MEASURE(S): Hormonal-follicular correlation. RESULT(S): Whereas, as expected, the correlation between FSH and follicle counts was affected by the presence of an overdeveloped follicle, the correlation between AMH and follicle counts remained unaffected. Estradiol failed to be correlated with antral follicle counts in both groups. CONCLUSION(S): In contrast with FSH, AMH levels remain tightly correlated to the number of antral follicles despite the presence of early growing follicles on cycle day 3.