Click here for Frequently Asked Questions on Postpartum Thyroiditis.
Fluctuating thyroid function after childbirth is common (5-10% of patients in some studies) and was first described in the 1970s. Thyroid inflammation may occur several months after childbirth, resulting in the development of clinical hyperthyroidism. Postpartum thyroiditis is not usually associated with a painful thyroid, hence most patients are not aware that there is an inflammatory process ongoing in their thyroid glands. Symptoms may initially include fatigue, anxiety, emotional lability, weakness, and many of the other common symptoms associated with hyperthyroidism. The initial hyperthyroid phase of the illness develops within one to six months following delivery (usually the first 3 months but occasionally later) and generally resolves without treatment after several weeks to a few months, and thyroid function will frequently return to normal.
In some patients, the hyperthyroid phase will be associated with significant damage to the thyroid as a consequence of the inflammation, and hence the hyperthyroid phase will be followed by the development of hypothyroidism.
Patients presenting in the hypothyroid phase generally will often become symptomatic months after delivery, but are occasionally asymptomatic, and the diagnosis may first be suspected based on screening tests such as a TSH.
It is important to remember that the symptoms of both hyper and hypothyroidism can be non-specific, and many women with a new baby have fatigue, inability to lose weight, aches and pains, and emotional lability, even in the absence of thyroid dysfunction.
The diagnosis is often made clinically, and as many women are still breastfeeding at the time of presentation, it is not generally desirable or necessary to stop breastfeeding for an uptake or scan as the diagnosis can usually be made on clinical grounds alone. Obviously, breastfeeding women should not have tests with radioactive isotopes as small amounts of the isotopes can be passed along in the breast milk, which is to be avoided.
Although thyroid dysfunction can clearly influence emotional lability and mood at any time, the vast majority of women with post-partum thyroiditis will not experience major depression as a result of the thyroid inflammation. See Postpartum thyroid dysfunction and postpartum depression: are they two linked disorders? Clin Endocrinol (Oxf). 2001 Dec;55(6):809-14.
Occasionally, thyroid function may not return to normal after postpartum thyroiditis and clinical persistent hypothyroidism may require treatment with thyroid hormone. For an overview of the relationship between postpartum thyroiditis, autoimmune thyroid disease, pregnancy, and the health of the mother and baby, see Postpartum thyroiditis and autoimmune thyroiditis in women of childbearing age: recent insights and consequences for antenatal and postnatal care. Endocr Rev. 2001 Oct;22(5):605-30.
I had a long lasting episode of postpartum thyroiditis with my last pregnancy. Will this happen again?
Patients with a history of a previous episode of postpartum thyroiditis are at increased risk of developing this problem again. Hence, these patients should be monitored after childbirth, with a TSH level periodically to detect the development of thyroid dysfunction.
How common is postpartum thyroiditis (PPT)?
PPT occurs in about 5-10% of all pregnancies and is most common in women with positive antithyroid antibodies. In some studies, about 20% of women with, and 5% of women without thyroid antibodies will develop PPT. See Postpartum thyroid dysfunction in women with normal thyroid function during pregnancy Clin Endocrinol (Oxf) 2000 Oct 13;53(4):487-492.
Will my thyroid function recover to normal after my episode of PPT?
In many studies, the majority of women will have complete recovery and not require thyroid hormone replacement. Nevertheless, some women may elect to be treated transiently, as the symptoms of fatigue and difficulty losing weight, which are common after pregnancy, may overlap with hypothyroid symptoms. Furthermore, about 25% of women may ultimately require thyroid hormone replacement of their thyroid function does not completely return to normal. See The biochemical and clinical course of postpartum thyroid dysfunction: the treatment decision. Clin Endocrinol (Oxf). 2001 Mar;54(3):377-383 and Postpartum thyroiditis and long-term thyroid status: prognostic influence of thyroid peroxidase antibodies and ultrasound echogenicity. J Clin Endocrinol Metab. 2000 Jan;85(1):71-5.
Can we prevent emotional problems or depression following birth by treating everyone with thyroid hormone?
In a randomized double-blind placebo-controlled trial, thyroxine or placebo was given daily to 446 thyroid-antibody-positive women (342 of whom were compliant) from 6 weeks to 6 months post-partum, with assessment of their psychiatric and thyroid status at regular intervals. The study showed that treatment with thyroxine had no effect on the occurrence of depression. See Randomized trial of thyroxine to prevent postnatal depression in thyroid-antibody-positive women. Br J Psychiatry. 2002 Apr;180(4):327-330.