Why You Need Thyroid Tests Before You Get Pregnant

Written by

For more than a decade, doctors have been disagreeing about the benefits of thyroid screening before or during early pregnancy, even though there is clear evidence that even mild hypothyroidism in a woman can cause infertility or miscarriage, and can negatively affect the health and cognitive function of the baby.

At the 2012 annual meeting of the American Thyroid Association, researchers distributed a survey asking about universal thyroid screening for pregnancy.

A total of 140 of the 561 endocrinologists at the meeting responded. A total of 74 percent were in favor of universal TSH screening during pregnancy; 18 percent opposed it, and 8 percent were unsure. The longer a doctor was in practice, the more likely he or she was to favor universal screening.

Even though universal thyroid screening is still not standard practice, if you are a woman planning to get pregnant, it’s a good idea to have your thyroid checked as part of your overall pre-conception evaluation. In particularly, have TSH, Free T4, Free T3 and Thyroid Peroxidase (TPO) antibodies checked.


If you have elevated TPO antibodies, or TSH, Free T4 or Free T3 are not optimized, it makes sense to discuss thyroid treatment with your practitioner before you try to get pregnant. (If you have a family history of thyroid and/or autoimmune disease, this is even more essential!)

It’s also important to evaluate thyroid function during the early part of the first trimester of pregnancy. Again, get TSH, Free T4, Free T3 and Thyroid Peroxidase (TPO) antibodies checked, and if there are any irregularities, they should be treated. For women diagnosed with thyroid disease during pregnancy, regular testing and adjustment of treatment is essential.

Important Note: TSH should always be below 3.0 during pregnancy, and below 2.5 during the first trimester.

Source:
Srimatkandada Pavani, Stagnaro-Green Alex, and Pearce Elizabeth N. “Attitudes of ATA Survey Respondents Toward Screening and Treatment of Hypothyroidism in Pregnancy.” Thyroid.December 23, 2014