The butterfly effect
You probably won’t know much about this small gland until something goes wrong with it. The thyroid gland is a butterfly-shaped gland situated in your neck, just in front of your throat. It produces hormones that affect various aspects of your metabolism such as energy expenditure, appetite and growth. Thyroid disorders are reasonably common, with around one in 20 people experiencing some form of thyroid disorder in their lifetime.
Thyroid problems are more common in women than in men, with two to five per cent of all women and one to two per cent of women of reproductive age being affected. Women who develop thyroid problems before, during or after pregnancy need particular care since their disease may affect not only their ability to conceive and maintain a healthy pregnancy, but also the wellbeing and development of the baby.
What sorts of effects can thyroid dysfunction have on fertility?
Mild to moderate hypothyroidism ( decreased thyroid hormone production) can cause increased menstrual frequency, but severe hypothyroidism can actually cause cessation of menstruation. Hyperthyroidism ( increased hormone production) can result in irregular or absent periods. Either way, there may be associated fertility problems. Fortunately, if either condition is recognised and adequately treated, fertility should be restored.
How do women with existing thyroid problems plan for a pregnancy?
If a woman has pre-existing hypothyroidism, the main thing is to ensure the ongoing adequacy of her thyroid hormone replacement during and after pregnancy. This minimises any risk to her or the baby. If a woman with hyperthyroidism wishes to fall pregnant it is best to ensure that her thyroid condition is treated and under control before conceiving, otherwise there is an increased risk of stillbirth and miscarriage. Radioactive iodine scans and radioactive iodine treatment cannot be given to pregnant women but there are medications that can be used to control thyroid function with minimal risk to the baby.
In some cases, where there is a serious problem with taking medication ( for example severe allergy), it may be necessary to operate during pregnancy to remove part of the thyroid, but this is rare.
What if thyroid dysfunction develops during pregnancy?
The most important thing is to recognise that the problem exists since some of the symptoms and signs of thyroid dysfunction, such as sweating, increased heart rate or palpitations, feeling tired, reduced concentration or brain fog, appetite changes, anxiety, constipation, weight changes and heat intolerance, may occur quite commonly even in normal pregnant women. It is normal for the metabolic rate to be raised in pregnancy, so it is not unusual for people to suspect hyperthyroidism. Similarly, the weight gain and sluggishness, lethargy, puffiness and brain fogginess of pregnancy may in some ways seem to mimic hypothyroidism.
If you have any concerns, your doctor can talk to you about your symptoms, examine you and do a simple blood test to assess your thyroid function. Fortunately, once recognised and diagnosed, most problems can be anticipated and effectively treated to allow a healthy outcome for mum and bub.