Postpartum thyroiditis

Postpartum thyroiditis

Having thyroid disorders during pregnancy means managing both pregnancy and thyroid problems with utmost care. This is because of the fact that untreated or overt hypothyroidism during pregnancy leads to adverse effects both to the fetus and mother. In fact, women have to take extra care even after delivery as they are prone to a condition called postpartum thyroiditis.

What is postpartum thyroiditis?

Thyroiditis means the inflammation of the thyroid gland and postpartum refers to the time after childbirth. Postpartum thyroiditis is a thyroid disorder that generally occurs in women during the first postpartum year. In this condition, the thyroid glands of the mother tends to get inflamed.

Postpartum thyroiditis is an autoimmune disorder that occurs in almost 8% of pregnant women around the world and in India. This condition is characterized by “transient” hyperthyroidism or “transient” hypothyroidism or transient hyperthyroidism followed by transient hypothyroidism. This condition is managed by endocrinologists.

Causes of Postpartum Thyroiditis

Pregnancy causes immense stress on the body. The entire body including thyroid glands undergo numerous changes. Till the first twenty weeks of gestation, the mother’s thyroid glands tend to overwork in order to provide thyroid hormones to the growing fetus. However, after twenty weeks of gestation, the baby starts to produce its own thyroid hormones.

Through the entire period of pregnancy, thyroid glands undergo major changes in terms of hormone levels and even the physical size. After delivery, the thyroid glands slowly tend to attain a “euthyroid” state in the first year of postpartum. Euthyroid is a state where the function of the thyroid gland has attained a normal state.

Along with changes in the thyroid gland, pregnancy also causes a special immunological condition. As if the burden of carrying a new life weren’t enough, pregnancy is also associated with immunosuppression. Though this does not mean that mothers are more susceptible to infections, it means that the immune system of pregnant women is unique considering that the fetus is also developing its own immunity at the same time.

However, some women who are prone to autoimmune thyroid disease, there is an immunological rebound after delivery subsequent to immunosuppression that occurs during pregnancy. This leads to postpartum thyroiditis.

Women prone to postpartum thyroiditis

  • Women with type 1 diabetes (as they have more thyroid antibodies)
  • Previous history of postpartum thyroiditis
  • Women with a family history of postpartum thyroiditis
  • Women with a history of other autoimmune diseases

How does postpartum thyroiditis affect women?

Though the manifestations of postpartum thyroiditis are not seen in the first six weeks postpartum, postpartum thyroiditis can present itself in the form of transient hypothyroidism, transient hyperthyroidism and in some cases, hyperthyroidism followed by hypothyroidism.

Postpartum thyroiditis is very similar to Hashimoto’s thyroiditis and causes the thyroid glands to be inflamed. As the thyroid glands have inflammation, they tend to produce more thyroid hormones. When the thyroid glands are stressed producing more thyroid hormones, it can lead to a state of underactive thyroid causing hypothyroidism.

While some women slowly reach euthyroid state, others are at a risk of having permanent underactive thyroid glands leading to hypothyroidism.

Stages & Symptoms of postpartum thyroiditis

Symptoms of postpartum thyroiditis are quite subtle, and most women experience symptoms as per the stage of their condition. In most cases, it goes totally undiagnosed until the patient experiences permanent hypothyroidism symptoms. That is why women need to get thyroid function tests even after pregnancy by consulting endocrinologists.

Hyperthyroid stage of postpartum thyroiditis

As a destructive thyroiditis caused by infiltration of lymphocytes, postpartum thyroiditis is a thyroid disease that is autoimmune in nature. In fact, women who have postpartum thyroiditis have thyroid autoimmunity (they test positive for thyroid antibodies) even before pregnancy.

In normal women, after delivery, thyroid glands move towards normal functioning (euthyroid state). In women with postpartum thyroiditis, there is an inflammation of the thyroid glands leading to increased production of thyroid glands. This leads to hyperthyroidism. In most cases, this hyperthyroidism resolves itself within 2 to 3 months. That is why it is called transient hyperthyroidism.

Transient hyperthyroidism in postpartum thyroiditis occurs generally before the 10th month postpartum.

Symptoms of transient hyperthyroidism in postpartum thyroiditis

  • Palpitations
  • Heat intolerance
  • Nervousness
  • Irritability
  • Fatigue

However, only some women experience symptoms. This condition is diagnosed by endocrinologists with a thyroid function test. The thyroid test shows low TSH levels and possibly high Free T4 levels.

Hypothyroidism stage of postpartum thyroiditis

This stage is characterized by a reduction of thyroid hormones leading to hypothyroidism. This stage is called transient hypothyroidism as the functioning of thyroid glands may come back to normalcy within the first year of postpartum.

Transient hypothyroidism may occur between the 2nd and 12th month of postpartum. Though it might not show up any symptoms in most women, those who experience generally have:

Symptoms of transient hypothyroidism in postpartum thyroiditis

  • Impaired concentration
  • Dry skin
  • Constipation
  • Poor memory
  • Decreased energy
  • Carelessness

Postpartum Thyroiditis Treatment

Treatment of postpartum thyroiditis depends upon the stage of the condition, providing relief from symptoms, and to address the possibility of heading towards permanent hypothyroidism. This is decided by endocrinologists.

In case of transient hyperthyroidism, for treating palpitations, beta-blockers are prescribed. If the transient hyperthyroidism does not show up any symptoms (is seen only in a thyroid function test), endocrinologists do not advice treatment.

In the transient hypothyroidism phase, again no treatment is provided if there are no visible symptoms. However, in case of symptoms, L-thyroxine therapy with levothyroxine is prescribed. The dosage and duration depends upon the test results and the discretion of the endocrinologist.

Thyroid function test as prescribed by an endocrinologist or an obstetrician plays an important role before, during, and after pregnancy. By frequent screening, women can avoid complications in pregnancy and avoid permanent hypothyroidism.