Hyperthyroidism In Pregnancy, What Should You Know?

The thyroid gland is a key organ in the body. During pregnancy it can change, sometimes in a normal way, and other times pathological. Today we are going to tell you about hyperthyroidism in pregnancy and everything you need to know about this condition.

Hyperthyroidism in pregnancy is one of the forms of thyroid pathology that occurs the least during pregnancy. It is estimated that it is present between 0.05 to 0.2% of women in this state.

It is not easy to diagnose hyperthyroidism in pregnancy, as physiological changes in the mother’s body may mask some symptoms. If the diagnosis is confirmed, it will have a very different treatment to that carried out in non-pregnant women. We will tell you.

Forms of hyperthyroidism during pregnancy

Thyroid function shows great changes in women during pregnancy. This is necessary for normal growth and development of the fetus to occur. Among the main transformations are the following:

• Sudden increase in the production of thyroxine: it occurs during the first trimester of pregnancy and can lead to transient hyperthyroidism.
• Elevation of thyroxine-binding globulin (TBG): TBG is a protein that transports related substances to the thyroid gland. Its concentration increases due to the increased production of estrogens during pregnancy.

• Changes in iodine reserves: there is a decrease in iodine before the 20th week of gestation, which is to be expected. This mineral is basic for the production of levothyroxine.

Hyperthyroidism in pregnancy is often transitory, when it is due to physiological changes or hyperemesis gravidarum, that is, morning vomiting. However, in most cases, the main cause is Graves’ disease.

This occurs in one in every 500 pregnant women and consists of an immune-based pathology that accelerates the functioning of the thyroid gland, overstimulating it. If it is not treated in time and properly, it can lead to serious complications for the mother and baby.

How is hyperthyroidism in pregnancy diagnosed?

Many of the manifestations of hyperthyroidism in pregnancy overlap in the changes produced by pregnancy. This means that the symptoms are masked and difficult to identify.

Signs such as heat intolerance, palpitations, nervousness, difficulty gaining weight, and tachycardia at rest are common features of hyperthyroidism and the pregnancy itself. The same goes for the increase in the volume of the thyroid gland.

Therefore, the results of biochemical tests must be carefully examined. In general, when the levels of TSH (thyroid stimulating hormone) are below the normal range and the levels of thyroxine (T4) and free thyroxine (FT4), or triiodothyronine (T3) are elevated, there is hyperthyroidism.

When there is Graves Basedow disease, it is exacerbated during the first trimester of pregnancy and postpartum. It is suspected to be present if the patient had symptoms prior to pregnancy, has a previous diagnosis of hyperthyroidism, or has had a child with thyroid dysfunction.

Risks of the disease

Hyperthyroidism in pregnancy can have very serious consequences, both for the mother and the fetus. Until after birth there are effects that last. So far, scientific evidence has identified the following complications:

• Increased risk of miscarriage.
• The risk of preeclampsia is multiplied by 5.
• There is 10 times more chance of premature delivery.
• The risk of heart failure is multiplied by 20.
• There is up to 10 times the risk of a thyroid storm.
• Increased risk of premature detachment of the placenta.
• More chances of suffering venous thrombosis.

This disease also poses risks to the baby. There may be stillbirth, growth retardation, neonatal goiter, congenital malformations, and low birth weight.

Treatment and follow-up

The basic treatment is usually carried out with antithyroid drugs. However, it is always necessary to make a prior analysis of the specific health condition of each woman to prevent adverse effects on her or the fetus.

Antithyroid drugs have teratogenic reactions, especially in the first trimester of pregnancy. The use of some of them has been associated with certain malformations and health problems in the fetus. Therefore, it is appropriate to do a strict monitoring to stop the medicine as soon as possible.

Most of the time, the goal of treatment is to keep thyroid hormone levels as close to normal ranges as possible. If there are very adverse drug reactions, surgery should be considered as the last alternative.

The optimal time to perform the surgical procedure is the second trimester of pregnancy. Anyway, after thyroidectomy it is necessary to continue with antithyroid medications.

Do not neglect thyroid control during pregnancy

Thyroid disorders occur more frequently in women of childbearing age. Therefore, this is one of the aspects to evaluate during pregnancy.

If the problem is present, it is essential to detect it in time, since the consequences of improper treatment can be very serious, both for the mother and the child. For this reason, prenatal controls and pregnancy planning as early as possible are essential to reduce risks.