Estradiol/Oestrogen (E2) Test

Estradiol is the most important form of estrogen found in the body, is produced and secreted by the ovaries, adrenal cortex and placenta. It is responsible for the growth of female uterus, fallopian tubes and vigina. It promotes breast development and growth of the secondary sexual characteristics in females. The hormone plays a role in the distribution of body fat in females and stops the process of growing taller. Estradiol is steroid hormone, which circulates predominantly protein bound. In addition to estradiol, other natural steroidal estrogens include estrone, estroil and their conjugates. Estradiol is metabolized to estrone and estriol by various target tissues. Estrogenic hormones are secreted at varying rates during the menstrual cycle throughout the period of ovarian activity. The gonadotropins of the anterior pituitary regulate secretion of the ovarian hormones, estradiol and progesterone. Hypothalamic control of pituitary gonadotropin production is in turn regulated by plasma concentrations of the estrogens and progesterone. During pregnancy, the placenta becomes the main source of estrogens. At the menopause, ovarian secretion of estrogens declines at varying rates. Clinical Significance: Greater than normal levels of estradiol may indicate: • Ovarian tumor • Gynecomastia • Pregnancy Decreased levels are implicated in following conditions: • Tumer’s syndrome • Menopause • Infection (mumps) • Resistant ovary syndrome • Primary hypofunction of ovary Additional conditions under which the test may be performed include: • Hypopitutarism • Infertility patients undergoing assisted reproductive technology