HYPOTHYROIDISM AND FERTILITY
WHAT IS THYROID
The thyroid gland is a butterfly shaped organ located in the base of your neck. A normal thyroid gland is not usually outwardly visible or able to be felt if finger pressure is applied to the neck. Its correct functioning depends on having a good supply of iodine from your diet. It releases hormones that control the body’s metabolism – the way your body uses energy. The thyroid is part of the endocrine system, which is made up of glands that produce, store, and release hormones into the bloodstream so the hormones can reach the body’s cells. The thyroid gland uses iodine from the foods you eat to make two main hormones:
- Triiodothyronine (T3)
- Thyroxine (T4)
It controls vital body functions which include
- Heart rate
- Menstrual cycles
- Body temperature
- Muscle strength
- Body weight
- Central and peripheral nervous system
- Brain development
- And much more….
It is important that T3 and T4 are neither too high nor too low. The two main glands in the brain, the hypothalamus and the pituitary gland control the amount of T3 and T4 production.
The hypothalamus produces TSH (Thyroid Stimulating Hormone) that signals the pituitary to tell the thyroid gland more or less T3 and T4 by either decreasing or increasing the TSH.
When T3 and T4 levels are low in the blood, the pituitary gland releases more TSH to tell the thyroid gland to produce more thyroid hormones. This condition is called hypothyroidism.
If T3 and T4 levels are high, the pituitary gland releases less TSH to the thyroid gland to slow the production of these hormones. This condition is called hyperthyroidism.
Listed below are some symptoms of too much T3 and T4 in your body (hyperthyroidism)
- Irritability or moodiness
- Nervousness, hyperactivity
- Sweating or sensitivity to high temperatures
- Hand trembling (shaking)
- Hair loss
- Weight loss
- Increased heart rate
- Missed or light menstrual periods
The following are a few symptoms that may indicate too little T3 and T4 in your body (hypothyroidism)
- Trouble sleeping
- Tiredness and fatigue
- Difficulty concentrating
- Dry skin and hair
- Low heart rate
- Weight gain or trouble losing weight
- Sensitivity to cold temperature
- Frequent, heavy periods
- Joint and muscle pain
HOW DOES HYPOTHYROIDISM AFFECT FERTILITY
Thyroid disorders are often known to cause significant reproductive problems in women and men. Abnormalities in thyroid function can have an adverse effect on reproductive health and result in reduced rates of conception, increased miscarriage risk, adverse pregnancy and neonatal outcomes.
Being Hypothyroid can cause
Ovulation problems – Hypothyroidism can cause anovulation (failure to ovulate) by causing an increase in the hormone called Prolactin, which is used by the body to assist with production of milk after delivery. Treatment with oral synthetic thyroid hormones can correct hypothyroidism, restore normal menstrual cycle and bring on ovulation.
Miscarriage – Studies show that women with both clinical and sub clinical hypothyroidism in early pregnancy are at an increased risk for miscarriage. Treatment with thyroid hormone can reduce the risk.
Hypothyroidism in pregnancy – The thyroid produces hormones that play key roles in the growth and development of the foetus. Changes in thyroid function can have a major effect on reproductive function before, during and after conception.
The developing foetus needs thyroxin and cannot produce its own until about the 10th week of gestation. Until such time, it depends on the thyroxin produced by the mother. If the mother suffers from severe hypothyroidism, it can result in complications including pre-eclampsia (High blood pressure), placental abruption, preterm labour and even fetal death. The babies can suffer from neurological impairment and mental retardation.
Having a thyroid malfunction can have an impact on your libido and can cause amenorrhea (absent period). Even in men, hypothyroidism can cause abnormal enlargement of the mammary glands and feminization along with loss of libido.
For women, treating hypothyroidism is an important part of any effort to correct infertility. If infertility remains after hypothyroidism has been corrected, other interventions to treat infertility may be needed.
If you have hypothyroidism and hope to become pregnant, work with your doctor to make sure your hypothyroidism is under control. Seek additional help from an infertility specialist if needed.