Follicle Stimulating Hormone (FSH) (Follicular Stimulating Hormone), Follitropin

Sample

1. It is done on the serum of the patient.
2. Record the date of the last menstrual cycle in women.
3. It is important to measure both FSH and LH levels.
4. Plasma and urine are also acceptable.
5. Sample stable 8 days at room temperature.
   1. 2 weeks at 4 °C.
6. The urine sample should not contain preservatives.
   1. Storage at or below -20 °C is recommended.
   2. 3 hours of urine samples are preferred.

Purpose of the test (Indications)

1. FSH ( along with LH ) helps to find whether the gonadal deficiency is of the primary origin or secondary due to insufficient stimulation of pituitary hormone.
2. FSH level helps to find the cause of hypothyroidism in women.
3. FSH level helps to find the cause of endocrine dysfunction in men.
4. FSH and LH are helpful in children with precocious puberty due to endocrine causes.
5. In the case of the Anovulatory cycle (infertility problems), serial estimation to see the peak in mid-cycle will be missing.
6. In primary ovarian or testicular failure, FSH is helpful where you will find an increased level.
7. FSH Help to find the cause of infertility.
8. FSH testing is commonly used to evaluate:
   1. Woman’s egg supply (ovarian reserve).
   2. Men’s low sperm count.
   3. To evaluate menstrual problems, such as irregular or absent menstrual periods (amenorrhea).
9. FSH can help to determine whether the woman has gone through menopause.
   1. FSH level is done in menopause.
10. FSH level is done in the case of abnormal vaginal or menstrual bleeding.
11. In men where there are no testicles or underdeveloped.
    1. In children, the FSH level is done if there is delayed puberty.
    2. FSH determines early puberty (also called precocious puberty ) or delayed puberty.
12. In children, the FSH level is done who develop sexual feature at a very younger age.
13. FSH diagnose certain pituitary gland disorders, such as tumors.

Precaution

1. Avoid hemolyzed, lipemic, or icteric samples.
2. HCG and TSH may interfere with some immunoassay. So patient with HCG producing tumor and Hypothyroidism patient will have a falsely high level.
3. The recent administration of radioisotopes interferes with radioimmunoassay estimation of FSH.

Pathophysiology

1. FSH is a glycoprotein secreted by the anterior pituitary gland and it is a pituitary hormone.
2. It consists of carbohydrates and two units of alpha and beta.

3. FSH is produced and stored in the pituitary gland.
4. FSH and LH hormones are secreted by the anterior pituitary gland.
   1. FSH is present in the plasma of males and females of all ages.
   2. Needed for the development of mature ova.
   3. It is also needed for the development of spermatozoa in males.

5. FSH is needed for the pubertal development and function of  ovary and testes:
   1. Stimulate follicles in the female.
   2. Stimulate the Sertoli cell development in the male.

6. FSH is under the control of:
   1. Hypothalamic-gonadotropin hormone (G N R H).
   2. Ovarian estrogen and progesterone in a female while testosterone in males when these are low.
   3. FSH acts on granulosa cells of the ovary and Sertoli cells of the testes.
7. FSH level increases at the time of puberty in both sexes.
   1. The amount of FSH varies throughout a woman’s menstrual cycle and is highest just before the ovulation.
      1. In the ovulating females, there is a sharp rise of FSH and LH  from the basal level just before the ovulation.
      2. FSH stimulates the formation of the follicle in the early stage of menstruation.
   2. The great increase in FSH and LH takes place in women after the menopause and remain elevated for the rest of life.
8. In male FSH and LH are necessary for the maturation of spermatozoa.

9. In the mid-cycle, a surge of LH leads to ovulation from the primed or active follicle.
10. It is one of the female hormones. In women, FSH helps control the menstrual cycle and ovulation by the ovaries.
11. In men, FSH helps control the production of sperm. The amount of FSH in men normally remains constant.

12. The FSH level can help determine whether male or female sex organs (testicles or ovaries) are functioning properly.

Normal value

Normal FSH

Source 1

Age	mIU/mL    Male	mIU/mL  Female
Prepuberty child
2 to 11 month	0.19 to 11.3	0.10 to 11.3
1 to 10 years	0.3 to 4.6	0.68 to 6.7
Puberty Tanner stage
1 -2	0.30 to 4.6	0.68 to 6.7
3 to 4	1.24 to 15.4	1.0 to 7.4
5	1.53 to 6.8	1.0 to 9.2
Adult	1.42 to 15.4
Follicular phase		1.37 to 9.9
Ovulatory phase		6.17 to 17.2
Luteal phase		1.09 to 9.2
Postmenopausal		19.3 to 100.6

To convert into SI units x 1.0 = IU/L

Another source

Women before puberty = 0 to 4 mIU/L

• Menstruating women
  1. Follicular  = 5 to 20 IU/L.
  2. Ovulatory phase = 30 to 50 IU/L.
  3. Luteal phase = 1.09 to 9.2 IU/L.
• Women post menopause = 19.5 to 100.6. IU/L.
• Men before puberty = 0 to 5 mIU/L
  1. Men during puberty = 1.42 to 15.4. IU/L
  2. Men  adult = 1.5 to 12.5 IU/L.
• Children:
  1. Male = 0.3 to 4.6 IU/L.
  2. Female = 0.68 to 6.7 IU/L.

Source 2

Sex	LH IU / L	FSH IU / L
Adult
Male	1.24 to 7.8	1.4 to 15.4
Female
Follicular phase	1.68 to 15	1.37 to 9.9
Ovulatory phase	21.9 to 56.6	6.17 to 17.2
luteal phase	0.61 to 16.3	1.09 to 9.2
Postmenopausal	14.2 to 52.3	19.3 to 100.6
Child
1 to 10 years: male	0.04 to 3.6	0.3 to 4.6
1 to 10 years: female	0.03 to 3.9	0.68 to 6.7

(Values vary from lab to lab. above data is from two sources)

Hormone cycles in the menstrual period:

Phase of cycle	LH	FSH	Progesterone	Estradiol
Follicular phase	low	High	low	low
Late follicular phase	High	low	lower limit	high
Mid-cycle	Peak	raised	increasing	low
Luteal phase	raised	raised	high	high
Start of Next cycle	low	rising	rising	rising

High FSH values in a woman:

1. Loss of ovarian function before age 40 (ovarian failure).
2. Polycystic ovary syndrome (PCOS).
3. Menopause has occurred.
4. Pituitary adenoma.
5. Precocious puberty.
6. Ovarian dysgenesis ( Turner syndrome ).

High FSH values in a man:

1. Klinefelter syndrome ( Testicular dysgenesis ).
2. Testicles are absent or not functioning properly.
3. Testicles have been damaged by a disease, such as alcohol dependence, or by treatments, such as X-rays or chemotherapy.
4. High values in children may mean that puberty is about to start.
5. Complete testicular feminization syndrome.

Decreased FSH values are seen in:

1. Pituitary failure.
2. Hypothalamic failure.
3. Stress.
4. Anorexia nervosa.
5. Malnutrition.

Low values indicate:

1. A woman is not producing eggs (prevents ovulation) leads to infertility.
2. A man is not producing sperm.
3. The hypothalamus or pituitary gland is not functioning properly.
4. A tumor is present that interferes with the brain’s ability to control FSH production.
5. Stress.
6. Starvation or are being very underweight.

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