Polycystic ovarian syndrome (PCOS) can often be a clinical diagnosis due to the classic distinguishing features of hirsutism, obesity, menstrual irregularities, and infertility. What is the classic relationship between FSH and LH in a patient with PCOS?
The classic relationship between LH and FSH in PCOS is > 2.5:1.
LH secretion is elevated, while FSH secretion is the same, or even decreased. LH stimulates theca cell proliferation and secretion of androgens, but there is insufficient FSH to stimulate granulosa cells. Although this is classically seen, LH:FSH is NOT used in any diagnostic criteria for PCOS.