Postpartum Thyroiditis: Signs and symptoms of thyroid issues during pregnancy

Pregnancy and childbirth is a crucial time for a woman’s health as the new mother is at risk of a number of diseases due to hormonal changes.

Postpartum thyroiditis is a condition where the new mother’s thyroid gland (the gland located in front of the neck) becomes inflamed after having a baby which may turn it overactive (hyperthyroidism) and then underactive after some time (hypothyroidism).

Women who have had family history of thyroid problems or type 1 diabetes may be more at risk of getting postpartum thyroiditis. How to know if you are suffering from this issue?

In the first phase of hyperthyroidism symptoms like nervousness, anxiety, fast heartbeat and weight loss can be observed while in the next phase of hypothyroidism, one may feel tiredness, have constipation, muscle cramps, weakness and weight gain. While in most women, the postpartum thyroiditis resolves after some time, for some the condition says lifelong and requires hormonal treatment.

Postpartum thyroiditis: How long it lasts

Postpartum thyroiditis may take up to one year to resolve bu affects a small percentage of women.

“Approximately 20 to 30 percent of people with postpartum thyroiditis have the characteristic sequence of hyperthyroidism, which usually begins one to four months after delivery and lasts two to eight weeks, followed by hypothyroidism, which also lasts from approximately two weeks to six months, and then recovery. Some individuals have only hyperthyroidism or only hypothyroidism,” says Dr Seema Sharma, Associate Director of Department of Gynecology and Obstetrics at Cloudnine Group of Hospitals, Chandigarh.

Signs and symptoms of postpartum thyroiditis

“The symptoms and signs of hyperthyroidism, when present, are typically mild and consist mainly of fatigue, weight loss, palpitations, heat intolerance, anxiety, irritability, tachycardia, and tremor. Similarly, hypothyroidism is also usually mild, leading to lack of energy, cold intolerance, constipation, sluggishness, and dry skin,” says Dr Sharma.

Diagnosis

“The diagnosis of postpartum thyroiditis depends on clinical symptoms and thyroid function tests (level of TSH and free T4). Levels of anti-thyroid peroxidase antibodies in Serum are high in 70-80 percent of patients with postpartum thyroiditis,” says Dr. Gunjan Bhola, Associate Director & HOD Unit 2, Obstetrics & Gynaecology, Marengo QRG Hospital Faridabad.

“Thyroid function tests may fluctuate during the course of postpartum thyroiditis, and changes in TSH concentrations lag behind changes in serum free T4. If the TSH is low, T3 should also be measured,” says Dr Sharma.

Screening

“For individuals at high risk for developing postpartum thyroiditis (eg, previously known to be thyroid peroxidase [TPO] antibody positive, type 1 diabetes, prior history of postpartum thyroiditis), we suggest screening for postpartum thyroiditis (Grade 2C). We typically measure a TSH level three and six months postpartum. If the TSH level is abnormal, it should be repeated along with a free T4 level and T3 (if TSH is low), within one to two weeks,” says Dr Sharma.

Treatment

Dr Sharma explains in detail the treatment for hyperthyroid and hypothyroid phase and the duration of the therapy.

Hyperthyroid phase

Most patients with postpartum thyroiditis do not require any treatment. Thyroid tests should be repeated in four to eight weeks to confirm resolution of hyperthyroidism. Beta blockers may be useful to relieve bothersome palpitations or tremulousness in symptomatic patients. If breastfeeding, we prefer propranolol because it has the lowest transfer into milk. There is no role for antithyroid drugs (ie, methimazole) or radioiodine in the treatment of the hyperthyroid phase of postpartum thyroiditis.

Hypothyroid phase

Symptomatic patients with an elevated TSH above the normal range require treatment with T4 (levothyroxine). For asymptomatic individuals with a TSH level ≥10 mU/L, we also suggest T4 replacement (Grade 2C). We do not routinely treat asymptomatic individuals with TSH levels below 10 mU/L.

Duration of therapy

Since postpartum thyroid dysfunction is often transient, we favour weaning T4 after 6 to 12 months, unless the person is pregnant, attempting pregnancy, or breastfeeding. The dose can be halved with assessment of thyroid function (TSH, free T4) six weeks later, and, if the TSH does not rise, stopped with reassessment of thyroid function after an additional six weeks.

Most patients recover and are euthyroid within one year postpartum. Up to 30 percent of individuals never recover from the initial hypothyroid phase and have permanent hypothyroidism.

Individuals with reversible hypothyroidism are also at increased risk for developing permanent hypothyroidism in the future and, therefore, require yearly monitoring of TSH.