Objective: To determine the prevalence of idiopathic hirsutism among a
population of consecutive hirsute patients. Design: Prospective cohor
t study. Setting: University-based clinic. Patient(s): Premenopausal w
omen with a complaint of hirsutism who were not receiving hormonal the
rapy. Intervention(s): Evaluations for total and free testosterone, (T
), 17-hydroxyprogesterone (17-HP), and DHEAS serum levels. Main Outcom
e Measure(s): Ovulatory function in women with cycles of less than or
equal to 35 days in length was assessed with a basal body temperature
(BBT) calendar and day 22-24 progesterone levels. Result(s): Of 132 co
nsecutive hirsute women studied, 68 had cycles of >35 days in length.
Of the remaining 64 patients, 25 also had oligo/anovulation by BBT and
day 22-24 progesterone level. Of the 39 patients with hirsutism and r
egular ovulatory function, 22 had total and free T and DHEAS levels wi
thin normal limits. Conclusion(s): If idiopathic hirsutism is defined
by the presence of hirsutism, regular ovulation, and normal androgen l
evels, only 17% of consecutive hirsute patients can be diagnosed with
the disorder. Alternatively, if idiopathic hirsutism is based solely o
n the presence of hirsutism and regular ovulation, regardless of andro
gen levels, then 29% of the total hirsute population can be considered
as having idiopathic hirsutism. Importantly, 40% of hirsute patients
with a history of ''regular cycles'' were actually oligo/anovulatory,
indicating the need to objectively assess ovulatory function in such p
atients. (Fertil Steril(R) 1998;70:274-8. (C)1998 by American Society
for Reproductive Medicine.).