PCOS

Polycystic Ovarian Syndrome is a condition that affects roughly 5% of women of reproductive age, and is characterized by the formation of multiple ovarian follicular cysts due to hormone imbalance.

Pathogenesis

The pathogenesis of polycystic ovarian syndrome in general is poorly understood, however the following is the current understanding:

  • Caused by genetics + diet and obesity
  • High GnRN => LH => androgen synthesis by theca cells => increased aromatization to estrone in peripheral adipose tissue => negative feedback to FSH => low FSH = cystic degeneration of follicle
    • insensitivity to progesterone leading to increased LH
  • Result: secondary amenorrhea and anovulation 
  • insulin resistance
    • Insulin => theca secretion of androgen and inhibition of sex-hormone binding globulin production => free androgens and androgen aromatization to estrone => negative feedback on FSH

Symptoms and Presentation

  • Increased androgens/testosterone: hirsutism, virilism (acne)
  • Suppression of FSH: secondary amenorrhea, infertility, multiple folicular cysts on ultrasound
  • Development of diabetes:

The classic presentation of a patient with polycystic ovarian syndrome is an overweight young woman presenting with infertility, oligomenorrhea and hirsutism. Some patients may also develop insulin resistance (seen in 50-70% of women with PCOS) leading to the development of type 2 diabetes mellitus 10-15 years later.

Women with PCOS experience prolonged exposure to unopposed, increased levels of estrone (no progesterone from corpus luteum) results in an increased risk of endometrial and breast cancer.

Diagnosis

Two out of three of the following criteria are required to make the diagnosis of PCOS:

  • Oligomenorrhea
  • Hyperandrogenism
  • Polycystic ovaries on ultrasound
  • LH:FSH ratio > 2

Treatments

The treatment for polycystic ovarian syndrome includes the following:

  • Oral contraceptives (OCPs) (primary treatment) 
  • Metformin and clomiphene citrate (used for women that desire to get pregnant)