New Diagnostic Option for Polycystic Ovarian Syndrome
Lilian White, MD
Posted on December 2, 2024
Polycystic ovarian syndrome (PCOS) is estimated to affect approximately 10% of women of reproductive age worldwide. PCOS tends to be underdiagnosed and is a leading cause of infertility. Patients with PCOS are more likely to develop hypertension, type 2 diabetes, hyperlipidemia, heart disease, and endometrial cancer, making diagnosis and early intervention potentially impactful on a patient’s long-term health. PCOS also increases the risk of miscarriage, pre-eclampsia, gestational hypertension, gestational diabetes, and cesarean delivery.
PCOS is a syndromic diagnosis, and there are no specific criteria that diagnose it unequivocally. Previously, guidelines have favored the Rotterdam criteria for the diagnosis of PCOS. In adults, meeting at least two of the three Rotterdam criteria (hyperandrogenism, polycystic ovaries, and irregular menses) supports a diagnosis of PCOS.
An updated international guideline by the PCOS Network adds the new diagnostic option of elevated antimüllerian hormone (AMH) levels in place of an ultrasonography showing polycystic ovaries to diagnose PCOS. AMH is solely secreted from ovarian follicles. This blood test is less invasive, more accessible, and less expensive than ultrasonography.
The etiology of elevated AMH in PCOS appears to be multifactorial and is incompletely understood. Genetics appear to play a role, with some studies implicating polymorphisms associated with AMH. Production of AMH also appears to be higher in the ovaries of women with PCOS.
AMH varies with age, body mass index, and laboratory results, so there is not yet a standardized threshold for diagnosis. An AMH cutoff value of 3.8 ng/mL when used in place of ultrasound criteria was estimated to be > 80% sensitive and specific for the diagnosis of PCOS in one study.
AMH levels are considered fairly stable and may be evaluated at any time in the menstrual cycle. AMH tends to be lower in patients with a higher BMI and recent or current hormonal contraceptive use. AMH should not be measured in adolescents for the purpose of diagnosing PCOS because it may be physiologically higher in this group. AMH peaks at about 20 to 25 years of age. An elevated AMH level is useful but not necessary for the diagnosis of PCOS. In the absence of other criteria, an elevated AMH level is insufficient for the diagnosis of PCOS.
AMH levels are also useful in the assessment of ovarian reserve, such as for the evaluation of infertility. An overview of the updated PCOS guideline is available in the November 2024 issue of American Family Physician.