High frequency of discordance between antimüllerian hormone and follicle-stimulating hormone levels in serum from estradiol-confirmed days 2 to 4 of the menstrual cycle from 5,354 women in U.S. fertility centers.

Objective: To determine the frequency of clinical discordance between antimüllerian hormone (AMH, ng/mL) and follicle-stimulating hormone (FSH, IU/L) by use of cut points defined by response to controlled ovarian stimulation in the same serum samples drawn on estradiol-confirmed, menstrual cycle days 2 to 4.

Design: Retrospective analysis.

Setting: Fertility centers in 30 U.S. states and a single reference laboratory with uniform testing protocols.

Patient(s): 5,354 women, 20 to 45 years of age.

Intervention(s): None.

Main Outcome Measure(s): Frequency of discordance between serum AMH and FSH values.

Result(s): Of the 5,354 women tested, 1 in 5 had discordant AMH and FSH values defined as AMH <0.8 (concerning) with FSH <10 (reassuring) or AMH ≥ 0.8 (reassuring) with FSH ≥ 10 (concerning). Of the women with reassuring FSH values (n = 4,469), the concerning AMH values were found in 1 in 5 women in a highly age-dependent fashion, ranging from 1 in 11 women under 35 years of age to 1 in 3 women above 40 years of age. On the other hand, of the women with reassuring AMH values (n = 3,742), 1 in 18 had concerning FSH values, a frequency that did not vary in a statistically significant fashion by age.

Conclusion(s): Clinical discordance in serum AMH and FSH values was frequent and age dependent using common clinical cut points, a large patient population, one reference laboratory, and uniform testing methodology. This conclusion is generalizable to women undergoing fertility evaluation, although AMH testing has not been standardized among laboratories, and the cut points presented are specific to the laboratory in this study.