Sex Hormones Tests
The sex hormone tests are ordered to determine if secretion of these hormones is normal. Estrogen fraction test is done to evaluate sexual maturity, menstrual problems, and fertility problems in females. This test may also be used to test for tumors that excrete estrogen. In pregnant women it aids in determining fetal-placental health. Estrogen fraction is also used to evaluate males who have enlargement of one or both breasts (gynecomastia), or who have feminization syndromes, where they display female sex characteristics.
Testosterone levels are ordered to evaluate:
- ambiguous sex characteristics
- precocious puberty
- virilizing syndromes in the female
- infertility in the male
- rare tumors of the ovary and testicle
The sex hormones control the development of primary and secondary sexual characteristics. They regulate the sex-related functions of the body, such as the menstrual cycle or the production of eggs or sperm. There are three main types of sex hormones:
- the female sex hormones (called the estrogen hormones)
- the progesterone hormones (which help the body prepare for and maintain pregnancy)
- the male sex hormones, or the androgen hormones
Female sex hormones are responsible for normal menstruation and the development of secondary female characteristics. Testosterone is a hormone that induces puberty in the male and maintains male secondary sex characteristics. In females, the adrenal glands and the ovaries secrete small amounts of testosterone.
Estrogen is tested to evaluate menstrual status, sexual maturity, and gynecomastia (or feminization syndromes). It is a tumor marker for patients with certain ovarian tumors. E1, a type of estrogen, is the most active estrogen in the nonpregnant female.
E3 (estriol) is the major estrogen in the pregnant female. It is produced in the placenta. Excretion of estriol increases around the eighth week of gestation and continues to rise until shortly before delivery. Serial urine and blood studies of this hormone are used to assess placental function and fetal normality in high-risk pregnancies. Falling values during pregnancy suggest fetoplacental deterioration and require prompt reassessment of the pregnancy, including the possibility of early delivery.
Progesterone is essential for the healthy functioning of the female reproductive system. Produced in the ovaries during the second half of the menstrual cycle, and by the placenta during pregnancy, small amounts of progesterone are also produced in the adrenal glands and testes.
After ovulation, an increase of progesterone causes the uterine lining to thicken in preparation for the implantation of a fertilized egg. If this event does not take place, progesterone and estrogen levels fall, resulting in shedding of the uterine lining.
Progesterone is essential during pregnancy, not only ensuring normal functioning of the placenta, but passing into the developing baby's circulation, where it is converted in the adrenal glands to corticosteroid hormones.
Testosterone is the most important of the male sex hormones. It is responsible for stimulating bone and muscle growth, and sexual development. It is produced by the testes and in very small amounts by the ovaries. Most testosterone tests measure total testosterone.
Testosterone stimulates sperm production (spermatogenesis), and influences the development of male secondary sex characteristics. Overproduction of testosterone caused by testicular, adrenal, or pituitary tumors in the young male may result in precocious puberty.
Overproduction of testosterone in females, caused by ovarian and adrenal tumors, can result in masculinization, the symptoms of which include cessation of the menstrual cycle (amenorrhea) and excessive growth of body hair (hirsutism).
When reduced levels of testosterone in the male indicate underactivity of the testes (hypogonadism), testosterone stimulation tests may be ordered.
The progesterone and testosterone tests require a blood sample; it is not necessary for the patient to restrict food or fluids before the test. Testosterone specimens should be drawn in the morning, as testosterone levels are highest in the early morning hours. The estrogen fraction test can be performed on blood and/or urine. It is not necessary for the patient to restrict food or fluids for either test. If a 24-hour urine test has been requested, the patient should call the laboratory for instructions.
Risks for these blood tests are minimal, but may include slight bleeding from the puncture site, fainting or feeling lightheaded after having blood drawn, or blood accumulating under the puncture site (hematoma).
Estrogen levels vary in women, ranging from 24–149 picograms per ml of blood. In men, the normal range is between 12–34 picograms per ml of blood.
Progesterone levels vary from less than 150 nanograms per deciliter (ng/dL) of blood to 2,000 nanograms in menstruating women. During pregnancy, progesterone levels range from 1,500–20,000 ng/dL of blood.
Testosterone values vary from laboratory to laboratory, but can generally be found within the following levels:
- Men. 300–1,200 ng/dL
- Women. 30–95 ng/dL
- Prepubertal children. Less than 100 ng/dL (boys), less than 40 ng/dL (girls).
Increased levels of estrogen are seen in feminization syndromes:
- when a male begins to develop female secondary sex characteristics
- during precocious puberty
- when children develop secondary sexual characteristics at an abnormally early age
- because of ovarian, testicular, or adrenal tumor
- during normal pregnancy, cirrhosis, and increased thyroid levels (hyperthyroidism)
Decreased levels of estrogen are found in the following conditions:
- a failing pregnancy
- during menopause
- anorexia nervosa
- primary and secondary hypogonadism
- turner's syndrome, seen in females with one missing X chromosome
Increased levels of progesterone are seen:
- during ovulation and pregnancy
- with certain types of ovarian cysts
- a tumor of the ovary known as a choriocarcinoma
Decreased levels of progesterone are seen:
- in toxemia of pregnancy
- with a threatened abortion
- during placental failure
- after fetal death
- with amenorrhea
- due to ovarian dysfunction
Increased levels (male) of testosterone are found in:
- sexual precocity
- the viral infection of encephalitis
- tumors involving the adrenal glands
- testicular tumor
- excessive thyroid production (hyperthyroidism)
- testosterone resistance syndromes
Decreased levels (male) of testosterone are seen in:
- klinefelter syndrome
- a chromosomal deficiency
- primary and secondary hypogonadism
- down syndrome
- surgical removal of the testicles
Increased levels (females) of testosterone are found in ovarian and adrenal tumors and in the presence of excessive hair growth of unknown cause (hirsutism).
Cahill, Mathew. Handbook of Diagnostic Tests. Springhouse, PA: Springhouse Corporation, 1995.
Pagana, Kathleen Deska. Mosby's Manual of Diagnostic and Laboratory Tests. St. Louis: Mosby, Inc., 1998.
Janis O. Flores