If you have been unsuccessfully trying to get pregnant for more than six months, before you embark on an invasive medical procedure and spend thousands of naira for assisted reproductive technology, ensure that your thyroid is functioning at its optimum.

Many women don’t realise that good thyroid function is necessary for fertility, the ability to conceive and to maintain a pregnancy.  A low or hyper-functioning thyroid gland can prevent you from achieving that much desired pregnancy. While there are many and varied reasons for infertility, suboptimal thyroid function may be that “missing link” – especially for those with no specific reproductive problems.

A full thyroid evaluation is essential and it should be done as soon as possible for any woman who wants to get pregnant, especially if she has any of the following:

The thyroid gland is located near the front of the throat, just below the voice box and just above the collar bones. Every cell in the body depends upon thyroid hormones for regulation of the body’s metabolism, blood calcium levels, energy production, fat metabolism, oxygen utilisation, balance of other hormones and weight maintenance.

If the pituitary gland is the headmaster of all endocrine glands that produce all hormones, the thyroid gland is like the deputy headmaster.

Hormones involved with thyroid function include Thyroid-Releasing Hormone from the hypothalamus in the brain, which stimulates the pituitary gland at the base of the brain to release Thyroid-Stimulating Hormone. The latter in turn stimulates the thyroid gland to produce Thyroxine and Triiodothyronine.

Much of T4 is converted to T3 (the active form) in the liver. Thyroid hormones are synthesised from iodine and the amino acid Tyrosine (from protein), and the conversion to the active form is reliant on the trace mineral selenium.

Healthy thyroid function can be affected by exposure to environmental toxins – electromagnetic radiation, chemicals and pesticides, heavy metals like mercury, lead and fluoride.

Other factors that disrupt normal thyroid functions include genetic susceptibility, high levels of stress, nutrient deficiencies, eating the wrong type of food, auto-immune disorders, infections and other hormone imbalances, such as estrogen dominance and high prolactin levels.

How does hypothyroidism affect fertility?

Anovulatory cycles – In this case the person is having a menstrual cycle but not releasing an egg (ovulating).  This makes pregnancy impossible.

Luteal phase problems – A person with a short second half of the menstrual cycle who gets a fertilised egg after intercourse will discover that such fertilised egg cannot implant securely and ends up leaving the body at the same time that menstruation would occur (very early miscarriage) and is often mistaken as a regular period.

High prolactin levels – due to elevated levels of Thyroid-Releasing Hormone and low levels of Thyroxine resulting in irregular ovulation or no ovulation.

Other hormonal imbalances – reduced sex hormone binding globulin, estrogen dominance, progesterone deficiency, all of which interfere with proper reproductive hormone balance.

A new study supports the notion that thyroid disorders can cause significant reproductive problems for women.

The report’s authors believe that testing for thyroid disease should be considered for women who have fertility problems and repeated early pregnancy loss.

Hypothyroidism is also associated with an increased risk of polycystic ovarian disease, a condition that causes cysts on the ovaries and inhibits pregnancy.

The research, published in The Obstetrician and Gynecologist, found that 2.3 per cent of women with fertility problems had an overactive thyroid compared with 1.5 per cent of those in the general population. The condition is also linked with menstrual irregularity, the researchers said.

“Abnormalities in thyroid function can have an adverse effect on reproductive health and result in reduced rates of conception, increased miscarriage risk and adverse pregnancy and neonatal outcomes,” said study co-author Amanda Jefferys in a news release.

She is a researcher from the Bristol Center for Reproductive Medicine at the Southmead Hospital in Bristol, England. We have noticed a strong link between hypo- and hyperthyroidism and infertility as well as adverse pregnancy and neonatal outcomes for over two decades.

Consequently, routine screening of the general population for thyroid dysfunction at the start of pregnancy and especially when seeking fertility treatment or struggling with miscarriage, it is highly recommended by experts.

The thyroid produces hormones that play key roles in growth and development. According to the British researchers, changes in thyroid function can have a major effect on reproductive function before, during and after conception.

Hypothyroidism (underactive thyroid) affects about 0.5 per cent of women of reproductive age. In children and teens, the condition is associated with a delay in reaching sexual maturity, according to published reports.

In adult women, hypothyroidism is linked with menstrual problems and a lack of ovulation in some cases.

The researchers also noted that thyroid disease is associated with an increased risk of problems during pregnancy, including miscarriage, preeclampsia, poor fetal growth, premature birth and stillbirth.

The thyroid evaluation can be done in any good laboratory and then interpreted by a doctor or better still an endocrinologist. There are  also new techniques using bio-energetic testing to determine whether the thyroid gland is stressed or weak at the preclinical state before it becomes pathological.

Finally, a good diet with iodide salt and good multivitamin supplement can provide a protection for the thyroid function.