22nd October 2015
The complex processes of ovulation, sperm production and fertilisation all need to work correctly to create a pregnancy. A third of infertility cases are attributed to the male, a third to the female, and the cause of the remaining cases is unknown.
Infertility can be caused by a variety of issues; some of which might be present from birth while others may develop as an individual ages.
While thyroid issues that lead to infertility are somewhat rare, at CRGH we always look at the thyroid as a possible cause during our preliminary investigation into a couple’s infertility. After all, when the thyroid does play a role in infertility, the risk of miscarriage is three times higher and pre-term births are double those where there is no thyroid problem.
So how does the thyroid affect fertility?
Abnormalities in thyroid function may have an adverse effect on overall reproductive health. These effects may include reduced conception rates, a higher risk of miscarriage, risky pregnancies and even neonatal problems. Disorders of the thyroid gland can even interrupt the menstrual cycle. For example, with hypothyroidism – an under active thyroid – your body doesn’t produce enough of certain hormones. This can reduce or even inhibit ovulation.
Many women with hypothyroidism are able to become pregnant but are at increased risk of miscarriage or even foetal development problems. During pregnancy, close monitoring of the thyroid and thyroid hormone levels is imperative to protect both the mother and baby.
Another way in which the thyroid affects fertility is through conception failure. The thyroid has an autoimmune function and thyroid autoimmunity has been linked to infertility and reproductive failure.
Testing for thyroid functionality
When diagnosing a woman with infertility it is important to test the thyroid, to eliminate it as a possible cause from the start. This is where the thyroid function test comes into play. The test involves checking for the patient’s levels of thyroid stimulating hormone (TSH) and can help determine the best course of fertility treatment.
Screening and subsequently treating thyroid problems in infertile women is extremely beneficial, as it may potentially be a way of reversing infertility, reduce the risk of miscarriage or pre-term birth, and may even prevent postpartum thyroiditis and depression.