Response of Treatment for Hypothyroidism on Infertility

Introduction

Child and motherhood are the two most important aspects of our social and family life. Also, these are one of the most important aspects of a woman's life. But infertility can be a hindrance in that path. One out of four couples and 48.5 million couple experience infertility. Around 15 % of women in the world are suffering from infertility. Finding the factors involved in infertility can help cure it and make many people smile.

What Is Women's Infertility?

Infertility is failure to get pregnant with frequent, unprotected sex for at least a year. The cause of infertility can be numerous. These causes are:

1. Damage and blockage in the genital tract.

2. Abnormalities female genital tract and sex organs.

3. Early stoppage of the menstrual cycle.

4. Presence of scar tissue.

5. Cancer and tumor.

6. Disorder in the production of eggs.

Hormonal imbalance causes ovulation disorder and is considered one of the main causes of infertility. Thyroid gland dysfunction and thyroid hormone imbalance are closely related to women's infertility. Around five percent of the world is suffering from hypothyroidism, and it causes infertility in around two to four percent of women.

What Is Hypothyroidism?

Hypothyroidism is a common condition characterized by the deficiency of thyroid hormone. The causes of hypothyroidism are:

1) Primary Hypothyroidism:

A disorder in the thyroid gland causes decreased thyroid hormone secretion. This is caused by:

• Deficiency in iodine intake.

• Autoimmune destruction of the thyroid gland: this is seen in Hashimoto’s disease (a type of auto-immune disorder) with anti-thyroid antibodies.

• Injury of the thyroid gland due to radiotherapy.

• Side effects of drugs: certain drugs like Amiodarone restrict thyroid hormone production through iodine overload.

• Partial removal of the thyroid gland during surgical procedures.

2) Central Hypothyroidism:

This is associated with disorders of the brain involving the hypothalamus and pituitary. This condition causes a low concentration of TSH (thyroid stimulating hormone) in the blood, which causes a reduction in the quantity of thyroid hormone. The causative factors are:

• Pituitary Apoplexy: Reduction in the blood supply in the pituitary gland. It is caused by a benign pituitary gland tumor creating a blockage in the blood supply. Hemorrhages or infractions (small thrombi in the blood vessels) may also be responsible for this.

• Sheehan’s Syndrome: This is caused by post-delivery necrosis of the pituitary gland. Post-delivery low blood pressure or shock is responsible for this.

• Pituitary Adenomas: These are the pituitary gland's slow-growing benign tumors involving the anterior portion. This slow-growing tumor causes blockage of the blood supply and reduction of pituitary hormone secretion.

3) Peripheral Hypothyroidism:

This is an extremely rare condition caused by the expression of the deiodinase 3 enzyme. This causes the inactivation of thyroid hormone. This hormone is high in human bone tumors, vascular anomalies like hemangioma (growth of blood vessels), and carcinomas.

The thyroid hormone is responsible for cellular functions like caloriegenesis (calorie formation) and oxygen consumption of mitochondria. So, a low thyroid hormone level is responsible for a reduced rate of cellular metabolism. The clinical symptoms of hypothyroidism are:

1. Fatigue.

2. Sudden weight gain.

3. Puffy face.

4. Hoarseness of voice.

5. Dry and coarse skin and hair.

6. Muscle pain and muscle weaknesses.

On examinations following signs are noted:

1) Cardiac Signs -

• Dyslipidaemia: Altered level of lipid and cholesterol.

• Bradycardia: Reduced heart rate.

• Increased thickness of blood vessels.

2) Neurological Signs -

• Reduced or sluggish tendon reflexes.

• Carpal Tunnel Syndrome: Numbness and tingling sensation in the fingers due to pressure on the nerves.

• Loss of hearing due to cochlear dysfunction.

3) Musculoskeletal Signs -

• Weak and brittle bone prone to fracture.

• Hoffman’s Syndrome: Weakness of muscles and reduction in their size.

What Is the Cause of Infertility in Hypothyroidism?

The mechanism of female infertility associated with hypothyroidism is as follows:

1. Hypothyroidism - In the early stage of life responsible for the delayed maturation of sexual organs and delayed onset of the menstrual cycle. In adults, hypothyroidism caused an altered menstrual cycle and increased blood flow. It is also responsible for the following:

• Amenorrhea: Absence or missing menstrual cycle.

• Menorrhagia: Heavy periods and excessive blood flow.

• Oligomenorrhea: Inconsistent blood flow during periods.

2. Anovulation - This condition happens when the egg (ovum) is not released from the ovary. Hypothyroidism is responsible for the altered peripheral metabolism of estrogens. Hypothyroidism is also responsible for higher biologically active androgens (a male sex hormone). These two factors are responsible for anovulation.

1. Normal levels of thyroxine and gonadotrophins are essential for normal fertilization rate and proper development of the fertilized egg. Thus, a low level of thyroxine is associated with an altered fertilization rate and failure in the maturation of the fertilized egg. The function of the ovarian cells responsible for sex hormone production is regulated by thyroxine. A low level of thyroxine is responsible for low levels of sex hormones in females.

2. Hypothyroidism is associated with delayed action of luteinizing hormone (LH) in response to gonadotropin-releasing hormone (GnRH). As a result, a delay in the maturation of the ovarian cell layers occurs, and irregular menstrual cycles can also be seen. An increased level of the prolactin hormone is seen in the case of hypothyroidism due to the action of the thyrotropin-releasing hormone (TRH, a hormone released from the hypothalamus). The high level of prolactin is responsible for dysfunction in the production of eggs.

Subclinical hypothyroidism is associated with increased levels of thyroid-stimulating hormone (TSH). This is associated with miscarriage and sexual organ dysfunction.

What Are the Diagnostic Test?

To identify hypothyroidism, blood tests are done.

1. Blood level measurement of thyroid stimulating hormone (TSH) and T4 (thyroid hormone) is evaluated., In cases of hypothyroidism, the TSH level is high, and the T4 level is low.

2. The TSH level in the second condition is high, but the thyroxine level and triiodothyronine (T3) are within the normal range. This is called subclinical hypothyroidism.

What Are the Treatment?

For the treatment of hypothyroidism, thyroid supplements can be provided. Levothyroxine is a synthetic version of the thyroxine hormone, which simulates the action of the thyroid hormone. It can also be used in subclinical hypothyroidism. Tumors can be removed surgically to eliminate obstructions.

Conclusion

Hypothyroidism is a common hormonal problem. Many women are suffering from this condition due to various issues. This is also responsible for sexual organ dysfunction and abnormal release of eggs. Synthetic thyroid supplements can help treat such patients and help cure infertility.