Polycystic ovarian syndrome is to some extent a diagnosis of exclusion. There is not a specific test that can be used to diagnose PCOS and there is not widespread agreement on what the diagnostic criteria should be. Your doctor will do tests to rule out other causes of anovulation and infertility. He or she will usually order a variety of hormone tests to help determine whether hormone overproduction may be due to PCOS, an adrenal or ovarian tumour, or an overgrowth in adrenal tissue (adrenal hyperplasia). Ultrasounds are often used to look for cysts in the ovaries and to see if the internal structures appear normal.
Your doctor will be looking for a combination of laboratory results and clinical findings that suggest PCOS. If you are diagnosed with PCOS, your doctor may order tests such as lipid profiles and glucose levels to monitor your risk of developing future complications such as diabetes and cardiovascular disease
- FSH (follicle stimulating hormone), will be normal or low with PCOS
- LH (luteinising hormone), will be elevated
- LH/FSH ratio. This ratio is normally about 1:1 in premenopausal women, but a ratio of greater than 2:1 or 3:1 may suggest PCOS
- Prolactin will be normal or mildly elevated (possibly due to chronic oestrogen exposure)
- Testosterone, total and/or free, usually elevated
- DHEAS (may be done to rule out a virilising adrenal tumour in women with rapidly advancing hirsutism), frequently mildly elevated with PCOS
- Oestrogens, may be normal or elevated
- SHBG (sex hormone binding globulin), may be reduced
- Androstenedione, may be elevated
- hCG (human chorionic gonadotropin), used to check for pregnancy, negative
- Lipid profile (low HDL, high LDL and cholesterol, elevated triglycerides)
- Glucose, fasting and/or a glucose tolerance test, may be elevated
- Insulin, often elevated
- TSH (thyroid stimulating hormone) to rule out hypothyroidism
Ultrasound, transvaginal and/or pelvic/abdominal are used to evaluate enlarged ovaries. With PCOS, the ovaries may be 1.5 to 3 times larger than normal and characteristically have more than 8 follicles per ovary, with each follicle less than 10 mm in diameter. Often the cysts are lined up on the surface the ovaries, forming the appearance of a "pearl necklace." These ultrasound findings are not diagnostic. They are present in more than 90% of women with PCOS, but they are also found in up to 25% of women without PCOS.
Laparoscopy may be used to evaluate ovaries, evaluate the endometrial lining of the uterus, and sometimes used as part of surgical treatment.