Estradiol Test (E2) - Serum

To measure or monitor your estrogen levels; to detect an abnormal level or hormone imbalance as a cause of your signs and symptoms; to monitor treatment for infertility or symptoms of menopause; sometimes to test for foetal-placental status during early stages of pregnancy

Your doctor may recommend an estradiol test if female or male sex characteristics aren’t developing at the normal rate. High estradiol levels may indicate early puberty and lower levels, late puberty. The symptoms include:

• bloating or swelling in your abdomen
• Loss of appetite
• pain in your lower abdominal and pelvic area
• weight loss
• frequent urination

Among the group of steroids, estrogens are responsible for development and also function of reproductive organs along with formation of secondary sex characteristics in women. Along with progesterone, another hormone, they help regulate the menstrual cycle, helps in growth of breasts and uterus along with maintaining a healthy pregnancy. Being a main sex hormone for women, they are also found in men and play an important role in growth and bone metabolism in both sexes. Estrogen tests measures one of three components- E1, E2, E3, in blood and urine.

• Estrone (E1) is directly converted from androstenedione (from the adrenal gland) or indirectly from other androgens. Ovaries, placenta, testicles, and adipose tissues also produce E1. E2 and E1 can be converted into each other as needed. E1 is the primary estrogen in men and in post-menopausal women.
• Estradiol (E2) is primarily produced in the ovaries in pre-menopausal women and in the testicles in men. E2 is converted from E1 in post-menopausal women. It is the most potent estrogen and the one that is present in the highest concentration in non-pregnant, pre-menopausal women. Women’s age and reproductive status decides the variation of E2 levels. They are a good marker of ovarian function.
• Placenta produces E3, and its concentration throughout a women’s pregnancy. Health of pregnant women and developing babies are indicated by its increasing levels. Estriol is part of the second trimester maternal serum screen, a test performed to evaluate foetal risk due to certain chromosomal abnormalities. Very low levels of E3 are present in non-pregnant women or men.

The test is used to assess the reproductive function in females. Problems caused by abnormal levels of estradiol include: menstrual irregularities, signs of menopause, infertility, gynaecomastia or a benign swelling of the male breast tissue etc. In males the estradiol test helps in the evaluation of gynaecomastia and in the diagnosis of estrogen-producing tumors

The test measures  the estradiol levels in the blood. 

This test requires a blood sample. A tourniquet (elastic) band is placed tightly on the upper arm. The patient is then asked to make a fist. This helps in the build-up of blood filling the veins. The skin is disinfected before needle insertion and the blood sample is collected in vacutainer. 

High levels may occur due to tumour of ovaries, or adrenal glands or due to early puberty.
 Low levels may occur due to ovarian insufficiency, early menopause, Turner's syndrome, or PCOS.