Estradiol – E2

Estradiol – E2

Estradiol is a steroid hormone that primarily regulates reproductive functions. It belongs to the group of estrogens and is considered its most active form. This biologically active compound is produced mainly in the ovaries, adrenal cortex, and placenta in women, and also in the testes in men. Additionally, a small amount of this hormone is produced by fat tissue cells, leading to increased concentration in overweight individuals.

The secretion of estradiol is regulated by ovarian hormones, follicle-stimulating hormones, and luteinizing hormones. During pregnancy, it is regulated by chorionic gonadotropin hormone. Before the age of ten, the levels of this compound in the blood are low, but with the onset of puberty, the concentration increases. Afterward, the hormone level depends on the menstrual cycle: it peaks in the follicular stage, then gradually decreases over two days until ovulation. It then decreases gradually until the next menstrual cycle. During pregnancy, the level of estradiol increases, but it decreases to normal levels on the fourth day after childbirth.

During uterine development, estradiol regulates the formation of female reproductive organs, then determines the psychological and physiological characteristics of behavior and the development of secondary sexual characteristics. Additionally, it affects bone growth, copper and iron binding, increases blood clotting, and participates in regulating kidney function.

For men, estradiol affects the function of the testes and prostate, and participates in fat and mineral metabolism. Its effect is not as pronounced as in women, due to much lower hormone concentrations in men.

Measurement of estradiol levels in the blood is recommended in the following cases:

  1. Menstrual cycle disorders.
  2. Infertility in both women and men.
  3. Failure to conceive.
  4. Menopause (to evaluate body condition and decide on alternative hormone therapy).
  5. Sexual development disorders: slow or accelerated.
  6. Gynecomastia (enlargement of male breast tissue).
  7. Disorders in the ovaries, testes, or accessory structures of the testes.
  8. Poor results in sperm analysis for men.
  9. Obesity and deterioration of liver fat.
  10. Osteoporosis.
  11. Suspected presence of tumors in the reproductive system: uterine fibroids, ovarian cyst, tumor, testicular or ovarian cancer, etc.

Regular monitoring of estradiol levels is advised during hormone therapy to assess its effectiveness, as well as for periodic diagnosis of ovarian condition, including preparation for assisted reproductive technology (in vitro fertilization).

Preparation for Analysis:

The analysis of estradiol levels is performed using the solid-phase chemiluminescent immunoassay technique. It requires a venous blood sample from the patient.

For the analysis, fasting is recommended on an empty stomach. Avoiding food for 8-12 hours before submitting the estradiol analysis sample is necessary, although drinking water is permitted.

Before undergoing the analysis, it is preferable to discontinue the intake of steroids, thyroid-stimulating medications, and some antibiotics, based on prior agreement with the treating physician, for two days before the test. For vegetarians, it is advisable to discuss dietary plans and avoid consuming large amounts of carbohydrates with reduced fat for several days, as this may lead to decreased estradiol levels and inaccurate results.

For women, estradiol levels in the blood are determined on days 2-4 of the menstrual cycle unless different instructions are provided by the treating physician. Exercise should be avoided, and stress minimized before the examination.

Estradiol Analysis Results (Estradiol – E2):

The analysis results are measured in picomoles per liter (pmol/L). Here’s how to interpret the results according to age and gender:

For Women:

  • 0-12 months: Less than 155 pmol/L
  • 1-5 years: Less than 90 pmol/L
  • 5-10 years: Less than 138 pmol/L
  • 10-14 years: Less than 355 pmol/L
  • 14-18 years: Less than 953 pmol/L
  • Over 18 years:
  • Follicular phase: 68-1269 pmol/L
  • Ovulation phase: 131-1655 pmol/L
  • Luteal phase: 91-861 pmol/L
  • Postmenopausal: Less than 73 pmol/L

For Men:

  • 0-12 months: Less than 85 pmol/L
  • 1-5 years: Less than 84 pmol/L
  • 5-10 years: Less than 69 pmol/L
  • 10-14 years: Less than 113 pmol/L
  • 14-18 years: Less than 182 pmol/L
  • Over 18 years: 40-161 pmol/L

Reference Values:

For women:

  • Estradiol levels in women depend on age and menstrual cycle stages.
  • Results should be interpreted by the treating physician, and any deviation from normal values requires additional diagnosis and consultation with a specialist.
Chemical Analysis:

Estradiol levels may increase due to reasons such as gynecomastia (increased breast fat in men), ovarian and testicular tumors, ovarian cysts, feminization syndrome (Morris syndrome), pregnancy or pre-ovulation status, increased secretion of thyroid hormones (hyperthyroidism), intake of certain hormone medications that increase estrogen secretion, liver fibrosis, onset of sexual maturity, adrenal cortex tumors (adrenal glands), and body fat excess.

Decreased values may result from conditions such as delayed sexual maturity, gonadal hypofunction (hypogonadism), loss of appetite (severe weight loss), menstrual cessation and postmenopausal stage in women, adrenal cortex dysfunction, polycystic ovary syndrome (PCOS), Shereshevsky-Turner syndrome, and decreased thyroid gland function.

Decreased estradiol concentration may also occur due to chemotherapy, intake of progesterone-only contraceptive pills, some antidepressants, and other medications.

  1. Sklyar N. V., Suturina L. V., Sholokhov L. F., Sharifullin M. A., Ermolova E. V. “Features of hormonal status in women with infertility associated with uterine fibroids.” Acta Biomedica Scientifica. 2005. No. 5.
  2. Lekareva T. M. “The role of sex steroids and prolactin in the pathogenesis of premenstrual syndrome.” Journal of Obstetrics and Women’s Diseases. 2007. No. 3.