Polycystic Ovarian Syndrome
last authored: March 2011, David LaPierre
last reviewed:
Introduction
Polycystic ovarian syndrome (PCOS) is an endocrine imbalance affecting 5-10% of women of reproductive age, with average onset at 15-35 years. It is characterized by chronic anovulation, as well as symptoms such as obesity, hirsuitism, and virilization. While the exact cause is unknown, gonadotropin dysfunction is commonly seen.
The Case of Karen L.
Karen is a 34 year-old woman who comes to you with a history of irregular periods over the past year. She has been trying to get pregnant for the past three years. Given her history, and obesity, you wonder if she might have PCOS.
- how would you go about making the diagnosis?
- what treatment(s) would you offer Karen?
Causes and Risk Factors
There are many conditions that can co-esist with PCOS, and it is difficult to know which causes which:
- obesity
- diabetes or insulin resistance
- hypertension
- hyperlipidemia
- obstructive sleep apnea
- breast cancer
- endometrial hyperplasia/carcinoma
Pathophysiology
Insulin resistance, and increased insulin levels, lead to elevated androgen production by the ovary, especially in patients with a genetic susceptibility.
Obesity leads to increased aromatase conversion to estrogen, which decreases FSH secretion and increases that of LH by acting on the pituitary. Increased ovarian secretion of androgens ensues, leading to hirsutism.
Gonadotropin dysfunction is usually seen, with an increased lutenizing hormone (LH) to follicular stimulating hormone (FSH) ratio. These appear to be mediated by deregulation of insulin and androgen, and also leads to increased testosterone production.
Increased LH and decreased FSH leads to anovulation, multiple cysts, oligomenorrhea, and infertility.
Signs and Symptoms
A diagnosis requires two of the following three:
- oligomenorrhea or irregular menstruation for >6 months
- evidence (clinical or lab) of hyperandrogenism
- polycystic ovaries
- history
- physical exam
History
Symptoms of PCOS include:
- amenorrhea (50%)
- abnormal uterine bleeding (30%)
- infertility
Past medical history
- acne
- gestational diabetes
- hypertension
- complete menstrual history
A family history of diabetes may be present.
Physical Exam
Vital signs: hypertension
Height, weight, and body mass index (BMI) should be ascertained.
Head and neck:
- acne
- hirsuitism
- deepened voice
Skin
- acanthosis nigricans, or the browning of skin folds, may also be present
- changes in hair pattern and growth
Genitalia:
- clitoromegaly
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
Testing should include:
- fasting glucose, or oral glucose tolerance
- hCG
- TSH
- prolactin
- FSH (to exclude premature ovarian failure)
- DHEAS and free testosterone are frequently increased; this is the most sensitive test
- 17-OH progesterone if congenital adrenal hyperplasia is suspected
- overnight dexamethasone suppression test to rule out Cushing syndrome
- endometrial biopsy to rule out hyperplasia/carcinoma
LH:FSH is increasingly believed to be of little or no value, though some still believe a 2:1 ratio may be helpful in diagnosis.
Diagnostic Imaging
Transvaginal ultrasound can show polycystic ovaries appearing like a string of pearls.
Laparoscopy is not necessary, but shows a white ovary with multiple follicular cysts.
Differential Diagnosis
Anovulation may be also be seen in:
- premature menopause (with elevation in both LH and FSH)
- rapid weight loss
- recent decontinuation of oral contraceptives
- pituitary adenoma and hyperprolactinemia
- hyperthyroidism or hypothyroidism
- endometrial hyperplasia or carcinoma
- acromegaly
- drug-induced hirsuitism
The differential of anovulation, polycustic ovaries, and high androgen levels can also be seen with:
- late onset congenital adrenal hyperplasia (21-hydroxylase deficiency)
- Cushing's syndrome
- ovarian and adrenal neoplasia
Treatments
Treatment depends on specific concern for patient.
Non-medications
If the patient is obese, weight-loss through excercise and diet is critical to reduce peripheral production of estrogen. Hirsuitism can be treated with hair removal, such as epilation or electrolysis.
Medications
If the patient wishes to become pregnant, ovulation may be induced by clomiphene citrate - an estrogen receptor blocker which works on the hypothalamus to induce LH/FSH. Oral hypoglycemics, ie metformin, reduce insulin resistance and can also induce ovulation. In vitro fertilization remains an option.
OCP or cyclic Provera can be used to prevent endometrial hyperplasia from excess levels of estrogen, as well as reduce hirsutism.
Spironolactone, dexamethasone, finasteride, or flutamide may all be used to reduce excess androgen production. These can be teratogenic, however, and should be used with caution.
Consequences and Course
Consequences include:
- obesity
- hyperlipidemia
- T2DM
- sleep apnea
- infertility
- endometrial neoplasia
Resources and References
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