584 Obstetrics and Gynecology Board Review •••
❍ What test should be ordered in suspected diagnosis of PCOS and why?
Fasting blood sugar or oral glucose tolerance test to rule out type II diabetes (FBS > 125 /OGTT >199) or impaired
glucose tolerance (FBS 101–125/OGTT 140–199); free testosterone, if not clinically hyperandrogenic to
help with diagnosis; total testosterone, if with hirsutism, to help rule out adrenal or ovarian androgen-secreting
tumor (>200 concern for ovarian tumor—pelvic U/S; >500–800 concern for adrenal tumor—CT scan or MRI);
DHEA-S if with hirsutism, to rule out adrenal source with CAH or tumor; 17-OH progesterone if with hirsutism,
to rule out CAH (5% of PCOS with hirsutism); prolactin if with hirsutism (hyperprolactinemia can cause
hirsutism); and TSH to rule out thyroid disease.
❍ What is the normal range of total serum testosterone in women?
Between 20 and 80 ng/dL.
❍ What range of total serum testosterone is typically seen in patients with PCOS?
Just above normal, typically <100 ng/dL.
❍ What are the abnormal feedback signals that may result in anovulation in the patient with PCOS?
Estradiol levels may not fall low enough to allow sufficient FSH response for the initial growth stimulus of oocytes.
This may result from excess estrogen production due to peripheral conversion in adipose cells of androgens
(principally androstenedione) to estrogens. The levels of estradiol may also be inadequate to induce the ovulatory
surge of LH.
❍ What happens to the surface area of the ovary in PCOS?
It typically doubles and the volume may increase up to 2.5-fold.
❍ Histologically, the PCOS ovary is characterized by?
Multiple atretic and cystic follicles, a thickened tunica (outermost layer), and a fivefold increase in stroma.
❍ How does weight loss in the obese patient with PCOS improve hyperandrogenism and anovulation?
Weight loss increases SHBG concentrations, thereby decreasing androgen levels; it also decreases the amount
of androgen converted to estrogen in adipose tissue. These effects combine to give a more normal pattern of
gonadotropin secretion leading to regulation of ovulation.
❍ What percentage of patients with PCOS placed on clomiphene citrate will ovulate?
80%, with pregnancy rates being approximately 40% to 60%.
❍ The spontaneous abortion rate in patients with PCOS is increased and may be as high as?
50%.
❍ What effects may the insulin-sensitizing agent metformin have in obese women with PCOS?
It has been reported to lower serum insulin, decrease serum free testosterone, increase serum SHBG levels, and
decrease ovarian 17a-hydroxylase and 17,20-lyase activity. However, further studies remain to be done to confirm
the clinical utility of metformin in this population of women. The weight loss experienced in these women may
also account for the observed effects.