Overactivity of the gland results in:

• Fatigue, restlessness, nervousness, irritability, increased appetite and weight loss, excessive sweating, heat intolerance and fine tremor. Some also notice difficulty in focusing the eyes, diarrhea, and rapid heart rate. These symptoms can have other causes as well.

A Typical Case

In a typical case of postpartum thyroiditis, a woman has a completely normal pregnancy and delivery. There is usually no history of thyroid disease, either in the past or during the pregnancy. Occasionally, she may have had a small goiter at one time, but no symptoms from it. Sometimes a close relative has thyroid disease.

One to three months after the birth of her child, she may or may not notice symptoms of hyperthyroidism (fatigue, nervousness, irritability, excessive sweating and intolerance to heat). The symptoms may be so mild that she does not even consult her doctor. If more severe, she will be prompted to see her doctor. Blood tests will then show elevated levels of anti-thyroid antibodies. This hyperthyroid state may be severe enough to require the use of anti-thyroid medications which suppress the activity of the thyroid gland.

Next, three to six months after the birth, a woman notices symptoms of an underactive thyroid (marked fatigue, lethargy, depression and cold intolerance). Blood tests then reveal a low level of thyroid in the blood as well as the presence of anti-thyroid hormones in the blood. This hypothyroid state may be so mild as to require no treatment. More often, a woman needs to take daily doses of thyroid hormone in a synthetic form called eltroxin or synthroid.

One year after delivery, the thyroid gland recovers from the temporary damage, and thyroid hormone levels go back to normal. At this point a woman can stop taking thyroid medication. In a very small percentage of cases, the thyroid gland does not recover and long-term use of medication may be required.

Borderline or chronic underactive thyroid can be missed in blood tests. A better way of detecting borderline hypothyroidism is to take the underarm temperature upon waking, before rising, each morning for three to five days or more (see chart). The average basal temperature is determined by the proper functioning of the thyroid gland, and a low body temperature on waking (below 97.8F or 36.55C) may indicate borderline hypothyroidism.

How Often Does This Occur

Postpartum thyroiditis may occur in anywhere between five and ten percent of all pregnancies. Some researchers suggest routine screening of woman after birth for blood levels of anti-thyroid antibodies. Postpartum thyroiditis can occur with first babies as well as second and third or more. Rarely, it even occurs after miscarriage or abortion. In the past, postpartum thyroiditis was probably often misdiagnosed as postpartum depression. But now it is both easy to diagnose and easy to treat. If a woman has had it once, it is likely to recur after each pregnancy, so both she and her physician will have to be on the look out for it.

Fatigue after childbirth is experienced by most women and is most often due to plain lack of sleep and the demands of new motherhood. Postpartum blues are usually due to a variety of factors including unrealistic expectations, lack of adequate support, and shifting hormone levels after birth. Ninety to 95 percent of women will not experience any difficulties with their thyroid gland after birth. For those who do, treatment is simple and effective.

For Further Reading

HYPOTHYROIDISM; THE UNSUSPECTED ILLNESS, by B. Barnes (Random House, 1974). This book goes into a lot of detail about undiagnosed thyroid problems, the basal temperature test, and how to treat and monitor problems.

POSTPARTUM DEPRESSION AND ANXIETY (1987) is a practical, self-help guide for helping mothers understand what is happening and what can be done. Available for $5.00 from Pacific Postpartum Support Society, 1416 Commercial Dr, Vancouver, BC, V5L 3X9. 604-255-7999.