Follicle-stimulating hormone (FSH) is one of the gonadotropins, a key hormone involved in the reproductive function and crucial for the woman’s fertility.
- Age 0-7 years: <6.7 mIU/mL;
- Age 8 years to adult:
- Follicular phase: 3.1-7.9 mIU/mL;
- Ovulation peak: 2.3-18.5 mIU/mL;
- Luteal phase: 1.4-5.5 mIU/mL;
- Postmenopausal: 30.6-106.3 mIU/mL;
- Age 0-7 years: <6.7 mIU/mL;
- Age 8 years-adult:1.3-19.3 mIU/mL;
The pituitary gland increases production of FSH when the values of sex hormones (estrogens, testosterone) are decreased due to various reasons. Increased FSH concentration may indicate one of the listed below conditions.
Primary ovarian insufficiency
A failure of the ovarian function in a woman under 40 years is referred to as ovarian insufficiency. Primary ovarian insufficiency occurs when the ovaries do not respond to the stimulation by the gonadotropins (FSH and LH). The disorder is characterized by the absence of the periods (secondary amenorrhea), low estrogen levels and increased gonadotropin concentrations.
Turner syndrome is a chromosomal abnormality characterized by the missing X chromosome in females whose karyotype is 45X0. Girls with Turner syndrome have short stature, webbed neck, swollen extremities due to lymphedema, primary or secondary amenorrhea (initial absence of the menstruations or their cessation), low thyroid function and heart defects. Some cardiovascular abnormalities observed in individuals with this syndrome may cause hypertension. Breast development may be absent, although pubic hair usually grows normally. Gonadal dysfunction results in infertility.
Swyer syndrome (also referred to as XY gonadal dysgenesis) is a disorder when a person with a typical male karyotype has a female appearance and female external genitalia. Usually, uterus and Fallopian tubes are also developed, but neither ovaries nor testes are present. Undeveloped gonadal tissues may be detected, they tend to become malignant at some point, so usually these residual tissues are removed surgically during childhood. Women with Swyer syndrome do not produce oocytes, although they may become pregnant with the help of reproductive technologies by using donated eggs. Hormone replacement therapy is recommended to sustain sexual development.
Congenital adrenal hyperplasia
Genetic disorders inherited as an autosomal recessive pattern that affects the synthesis of glucocorticosteroids, mineralocorticoids and sex hormones cause the congenital adrenal hyperplasia. A manifestation of the disease varies greatly according to the sex of the child and genetic mutation seen in an individual. Congenital adrenal hyperplasia impairs sexual development, result in abnormal puberty and infertility.
Primary male hypogonadism, also known as a testicular failure, is caused by the insufficient production of testosterone by the testicles. Other symptoms of the disorder are the absence of secondary sex characteristics, sexual dysfunction (erectile dysfunction, decreased libido), decreased fertility due to oligospermia or azoospermia, loss of muscle and bone mass, depression and irritability. A person may also experience hot flashes.
Complete testicular feminization syndrome
Androgen insensitivity syndrome (also known as testicular feminization syndrome) is a condition in which the cells do not respond to androgens. This “resistance” to androgens interferes with the development of male genitalia, male secondary sexual characteristics also do not develop. Of note, females may also be insensitive to androgens, although in this case the androgen unresponsiveness has no clinical significance in contrast to the significant effects in Y-chromosome carriers (genetically males). The degree of masculinization may vary from complete to partial androgen insensitivity. In complete androgen insensitivity person’s external genitalia have a normal female appearance, whereas the karyotype is 46, XY.
Klinefelter syndrome is a chromosomal abnormality in which a person with a male karyotype has an extra X chromosome (47, XXY). Males with Klinefelter syndrome have underdeveloped small testicles (microorchidism, sometimes undescended testicles), which do not produce enough testosterone leading to infertility and delayed or incomplete puberty. Other symptoms of the disorder include muscle weakness, enlarged breasts, tall stature, and small penis. Intellectual development may also be compromised.
Systemic Lupus Erythematosus
Systemic lupus erythematosus is an autoimmune disorder which involves various organs, causing joint pain, arthritis, low-grade fever, muscle aches, hair loss, and characteristic butterfly rash on the face. It is considered that in SLE reproductive system may also be affected – antibodies to corpus luteum are detected in blood. Involvement of the reproductive system increased FSH values in the serum.