Thyroid hormones regulate the body’s metabolism and affect nearly every organ in the body. When the body produces too much thyroid hormone (hyperthyroidism) it causes many functions is the body to speed up too much. When the body produces too little thyroid hormone it causes many of our body functions to slow down (hypothyroidism).

It’s well-known in the medical community that the thyroid plays a critical role in the development of a healthy baby as well as maintaining the health of the mother. Women with hypothyroidism can have a healthy pregnancy by being aware of how their pregnancy affects the thyroid and taking the required treatments and medications. Because the risks to the baby and mother are very real, if a hypothyroid woman does conceive, she may be at significantly higher risk for miscarriage, stillbirth, placental abruption, preterm birth and preeclampsia.

Fortunately, statistics say that if thyroid treatment successfully normalizes thyroid levels, then the risks are the same as for healthy women.

Pregnancy Risks For Women With Subclinical Hypothyroidism

WebMD defines subclinical hypothyroidism as being diagnosed under the following conditions: 1) No symptoms or mild symptoms of hypothyroidism. Examples are fatigue, cold intolerance, consistent weight gain, depression, or memory problems. 2) Having a mildly high TSH (thyroid-stimulating hormone, the marker which is increased when thyroid hormone is low) 3) Having a normal thyroxine (T4) level.

Subclinical hypothyroidism seems to be a grey area for physicians as there is great debate among doctors regarding best treatment. In fact, the American Thyroid Association currently does not recommend treatment, calling the data unclear. Many women with this diagnosis may have low body temperatures and still suffer the symptoms. And low body temperatures can also make it difficult for women to conceive.

A recent study addressed the concerns of subclinical hypothyroidism in pregnancy and the risk of miscarriage. This study is a meta-analysis, meaning it looked at a group of older studies which all have similar themes, and determined what the overall outcome was when looking at the entire group of research as a whole. This particular meta-analysis reviewed seven older studies which first analyzed the risk of miscarriage in women who were diagnosed with subclinical hypothyroidism, but weren’t being treated. It was determined that overall, women in this situation had significantly greater risk of having a miscarriage as compared to women with healthy thyroid levels.

There was good news, however. The study also looked at risks for women with subclinical hypothyroidism who were being treated effectively (normalizing their TSH levels), and found that treatment lowered their risk of miscarriage significantly, as compared to the women who were not treated.

This article also noted that as TSH levels increased, the risk of having a miscarriage increased proportionately.

In pregnancy, the parameters for TSH and thyroid levels are different than the levels for a non-pregnant women. In 2017, the American Thyroid Association gave new guidelines which lowered the upper limit for TSH (by .5 mU/L) in pregnant women, so many more would fall into the diagnosis of hypothyroidism and would qualify for treatment. Nevertheless, the ATA still does not recommend treating subclinical hypothyroidism.

Yet, the findings from this meta-analysis study strongly suggests that treating women with subclinical hypothyroidism significantly reduces their chances of having a miscarriage as compared to women without treatment.

For women trying to conceive, it’s highly likely that women with Wilson’s Temperature Syndrome (WTS) would face the same obstacles as women with subclinical hypothyroidism and would benefit from normalizing their low body temperatures even when their TSH levels are normal. To learn more about WTS and how to diagnose it simply by taking your temperature, please see these guidelines
http://www.wilsonssyndrome.com/identify/how-are-body-temperatures-measured/

Reference:
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0175708