Estrogen Tests: What They Are and When You Need Them

Why Estrogen Tests Are Ordered

There are three main forms of estrogen tested clinically — estrone, estradiol, and estriol — and each has specific applications:

• Estrone levels may be elevated in patients with polycystic ovarian syndrome and endometriosis. Tests may also aid in the diagnosis of ovarian tumors, Turner syndrome, and hypopituitarism. In males, elevated estrone may help diagnose gynecomastia or estrogen-producing tumors.

• Estradiol is used to evaluate ovarian function. Elevated levels are seen in early (precocious) puberty in girls and gynecomastia in men. Its main use is in the differential diagnosis of amenorrhea — determining whether the cause is menopause, pregnancy, or a medical problem. In assisted reproductive technology (ART), serial measurements monitor follicle development prior to in vitro fertilization.

• Estriol may be ordered serially to monitor a high-risk pregnancy. Unconjugated estriol is one component of the triple or quad screen. Decreased levels have been associated with genetic disorders including Down syndrome and neural tube defects.

When Is It Ordered?

A doctor may order estrogen tests when a woman has symptoms such as pelvic heaviness, abnormal vaginal bleeding , irregular menstrual cycles, infertility, or early or delayed puberty.

Estrogen tests are also ordered when a woman experiences hot flashes, night sweats, insomnia, or amenorrhea — symptoms of menopause. During hormone replacement therapy, doctors may periodically monitor estrone levels.

For fertility problems, estradiol measurements track follicle development prior to IVF. Estradiol testing may also be ordered when a man shows signs of feminization, such as gynecomastia.

What Does the Test Result Mean?

Estrogen levels vary on a day-to-day basis and throughout the menstrual cycle. A doctor monitoring hormones will look at trends over time rather than evaluating a single value.

Increased estrogen levels are seen in:

• Normal menstrual cycle
• Early (precocious) puberty
• Gynecomastia
• Tumors of the ovary, testes, or adrenal glands
• Hyperthyroidism
• Cirrhosis

Decreased estrogen levels are seen in:

• Turner syndrome
• Hypopituitarism
• Hypogonadism
• Failing pregnancy (estriol)
• Anorexia nervosa
• After menopause (estradiol)
• PCOS (Polycystic ovarian syndrome)
• Extreme endurance exercise

Additional Considerations

Blood and urine results are not interchangeable. Your doctor will choose the sample type based on the clinical question being asked.

Certain drugs can affect estrogen levels. Drugs that increase levels include glucocorticosteroids, ampicillin, and tetracyclines. Drugs that may decrease levels include clomiphene and oral contraceptives.

Common Questions

Do men have estrogens? Yes. Although present in much lower amounts than in women, estrogens are necessary in men for hormonal balance and glandular function.

What are estrogen receptors? **Proteins located on cells from certain tissues that bind with estrogen. Excess estrogen exposure can stimulate cell growth in estrogen-receptor-positive tissues.**What are phytoestrogens? Estrogen-like compounds from plant sources — primarily isoflavones (soy products) and lignans (whole grains, some fruits and vegetables). Initial studies show they may relieve some menopausal symptoms such as hot flashes, though more research is ongoing.

What are environmental estrogens? Chemicals, either natural or synthetic (such as the insecticide DDT), that mimic estrogen and may cause disorders such as infertility, endometrial overgrowth, and feminization. They tend to remain in the body for long periods and are under ongoing study.