Thyroid Screening for At-Risk Women May Help Pregnancy

Thyroid disease screening advised for women with fertility issues and miscarriages

(RxWiki News) Decorate the baby's room, buy baby clothes, plan for the baby's future. Planning for pregnancy can be hectic, but many women may want to ask their doctor about one more thing: thyroid screening.

A new review found that thyroid diseases had a major effect on women’s reproductive health. This review pointed out that improving thyroid health may greatly lower the risk of reproductive health issues in women.

The authors of this review said that women who have fertility problems should be screened for thyroid disorders to avoid complications. Screening was especially recommended for those trying to get pregnant and who had had miscarriages before.

Amanda Jefferys, BMBS, BMedSci, of the Southmead Hospital in Bristol, UK, led this study.

“Abnormalities in thyroid function can have an adverse effect on reproductive health and result in reduced rates of conception, increased miscarriage risk and adverse pregnancy and neonatal outcomes,” Jefferys said in a press release.

Jefferys continued, “However, with appropriate screening and prompt management, these risks can be significantly reduced.”

The thyroid is a gland that is shaped like a butterfly and sits on the windpipe in the front neck area. The thyroid releases hormones that control a host of chemical processes in the body. These hormones play key roles in growth and development — brain development in particular. Changes in thyroid function can greatly affect reproduction, Jefferys and colleagues said.

Hyperthyroidism is a condition in which the thyroid is overactive. When the thyroid is underactive, the condition is called hypothyroidism.

This review found that almost 2.3 percent of women with fertility issues had hyperthyroidism. In contrast, 1.5 percent of women in the general population (without fertility issues) had hyperthyroidism. Hyperthyroidism, according to the review, affects about 0.5 percent of women who are able to have a baby (15 to 49 years old).

The authors of this study found that thyroid problems in women were linked to fertility problems, irregular menstrual cycles, delayed reproductive maturity and, in some cases, a lack of ovulation (when an egg is released from the ovary).

Jefferys and team also linked thyroid problems to miscarriages. In fact, almost 1 in 5 pregnant women with a thyroid disease had a miscarriage, these researchers found. Recurrent miscarriage, defined as three miscarriages in a row, affects 1 percent of couples. Thyroid hormones play a crucial part in the development of the embryo. Thyroid disease has been linked to an increased risk of miscarriage for a long time.

These researchers found that hyperthyroidism, in particular, resulted in adverse pregnancy results. Adverse outcomes included early delivery, preeclampsia (high blood pressure and protein in urine during pregnancy), highly stunted growth, heart failure and stillbirth.

Thyroid disease screening among at-risk women, especially at the start of pregnancy, may lower the risk of these complications, Jefferys and team said. They also noted that women diagnosed with thyroid diseases should be closely monitored during pregnancy.

Jefferys and colleagues concluded that "with appropriate screening, a high index of suspicion and prompt management, risks can be significantly reduced."

This review was published Jan. 23 in The Obstetrician & Gynaecologist.

The authors disclosed no funding sources or conflicts of interest.

Review Date: 
January 23, 2015