Your thyroid is a crucial gland that produces hormones that help deliver oxygen and energy to your cells. Thyroid hormone is essential for survival. Thyroid hormone is also essential to get pregnant, maintain your pregnancy, and have a healthy baby.
It's estimated that as many as 60 million Americans are have an underactive or non-functioning thyroid, which produces a condition called hypothyroidism. Here are some startling statistics:
- The vast majority of people with hypothyroidism--as many as 40 million or more--are currently undiagnosed.
- The vast majority of people with hypothyroidism--diagnosed or undiagnosed--are women, and many of them are of childbearing age.
If you are pregnant, having undiagnosed, untreated, or poorly treated hypothyroidism increases your risk of a variety of frightening outcomes, including an increased risk of miscarriage, stillbirth, prematurity/pre-term labor, and other complications for you and your baby.
Doctors and obstetricians should know this. But many don't. Even cases of overt hypothyroidism--where the popular Thyroid Stimulating Hormone (TSH) levels are above 10 mIU/L--are often overlooked and go untreated. These women often face early miscarriage, later pregnancy loss, and other complications.
New research was just released, and it makes the situation even more critical for women. The study showed that treating women with mild--what's called subclinical hypothyroidism (a TSH levels less than 10.0)--may help reduce your risk of having a premature baby, an early cesarean section, or a stillborn baby.
In November, Dr. Peter Taylor of the University of Cardiff in Wales released research findings at the Society for Endocrinology annual conference in Brighton, England. Dr. Taylor's study looked at 13,000+ women who were 12 to 16 weeks pregnant. They identified 518 women in the group who had subclinical hypothyroidism. They then split the group, with half receiving the thyroid hormone replacement drug levothyroxine (i.e., Synthroid, Levoxyl), and the other half going untreated. The rates of stillbirth, neonatal death, delivery before 37 weeks, and early cesarean sections were then evaluated among both groups of women.
Again, some important findings.
- Untreated women with subclinical hypothyroidism had a higher risk of stillbirth
- Treating treated women with subclinical hypothyroidism had a reduced risk for prematurity, low birth weight at delivery, and early cesarean sections.
Here is a quote from Dr. Taylor:
Our work raises the possibility of providing real benefits from using a safe, cheap and well-established treatment by simply extending it to the number of pregnant women we treat. We should consider universal thyroid screening in pregnancy as it compared favorably in terms of cost-effectiveness with other conditions that we currently screen for.
Endocrine Today also interviewed Dr. Taylor, who had this to say:
We have indicated that there may be real benefits from correcting borderline thyroid function in pregnant women using a commonly used inexpensive drug, levothyroxine. This has important outcomes, including reducing stillbirth and prematurity, although more studies are needed. It also raises the possibility that as hypothyroidism and borderline thyroid function are common, there is a compelling argument for universal thyroid screening in pregnancy. More focus on thyroid status is needed as well as consideration of universal thyroid screening.
What Should You Do?
1. Treat Subclinical Hypothyroidism BEFORE Pregnancy
If you have subclinical hypothyroidism, and you are planning to have a baby--but your doctor has said that thyroid treatment is not needed--you should either ensure that your doctor gets up to speed on proper guidelines for managing thyroid disease during pregnancy, or get a new doctor who IS already up to speed, and who will treat you.
You may want to point your doctor to the official "Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease during Pregnancy and Postpartum," which state that for women who are hypothyroid (even subclinically), the dosage of thyroid hormone replacement medication should ensure that the TSH is below 2.5 mIU/L BEFORE you get pregnant. (And remember, 2.5 is in the middle of the so-called "normal" or reference range. So your doctor saying "your thyroid is normal" is meaningless. You MUST ask for the actual number, and if it's above 2.5, take action before you get pregnant.)
2. Confirm Your Pregnancy Rapidly and Have a Plan
Assuming that your hypothyroidism is being treated, and your TSH is below that 2.5 level, you should also have a plan with your doctor about how much to increase your dose the moment that you confirm your pregnancy. And you will want to test early and often to confirm your pregnancy. (Some home pregnancy tests can confirm pregnancy as early as 7 days post-conception.)
During the first trimester, your developing baby gets all his or her thyroid hormone from you, and if you don't have enough, not only your baby’s neurological and physical development--but the pregnancy itself--is at risk. This increased demand means that most women need as much as a 50% increase in thyroid hormone during the first trimester of pregnancy. This means that confirming your pregnancy early, and increasing your medication right away--and scheduling a followup blood test with your doctor soon after--are crucial steps to help protect the health and development of your baby and the viability of your pregnancy.
3. Confirm and Treat Subclinical Hypothyroidism During Pregnancy
Early pregnancy is known for a variety of symptoms. Unfortunately, many of these symptoms are the same for mild hypothyroidism. If you have any of the following symptoms, it's far better to be safe, and insist on thyroid testing.
___ Fatigue, unrefreshing sleep
___ Unusually rapid weight gain, despite no change in diet
___ Depression, anxiety, or moodiness
___ Increase in hair loss, loss of hair in the outer edge of your eyebrows
___ Puffiness around the eyes
___ Puffiness or swelling in your hands or feet
___ Constipation that is unrelieved by treatment or dietary changes
If the tests show that you have subclinical or overt hypothyroidism, insist on treatment immediately.
4. Know the Guidelines
When you have your thyroid tested via a TSH test, the level will only be flagged as abnormal if it is above or below the reference range, which typically runs from around 0.5 to 5.0 mIU/L.
This normal “reference range” is thrown out the window during pregnancy! The actual reference range for a women during pregnancy is far narrower. The official guidelines from the endocrinology community say that your TSH level during your first trimester should never go above 2.5 mIU/L, 0.2 to 3.0 mIU/L, and never above 3.0 mIU/L during our second and third trimesters.
Again, a TSH above 2.5 will NOT be flagged as abnormal on your blood test results, which means that an elevated level may not even get your doctor’s attention. Even then, the doctor providing your pregnancy care may not be aware of the guidelines, or if he or she is aware, may choose to ignore them. And believe me, some do. Thyroid advocate Dana Trentini—“HypothyroidMom”—was told by a top, New York City based physician that her first trimester TSH levels above 9 were “normal” — right before she miscarried.
Don't be a victim of medical ignorance! I know it sounds ridiculous, but studies have shown that a substantial percentage of both obstetricians and endocrinologists have no idea how to properly manage thyroid disease in pregnancy. You should NEVER assume your doctor knows about the guidelines, or is following them. Make sure that you are tested, properly treated, and that your thyroid disease is managed correctly during pregnancy.
P.S. Does your doctor want sources for this information, or do you want to print out the Guidelines and share them with your physician? Here are the citations:
- Stagnaro-Green, Alex, et al. "Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and Postpartum." Thyroid. Volume 21, Number 10, 2011 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3472679/
- Taylor PN, et al. Abstract #OC6.3. Presented at: Society for Endocrinology Annual Conference; Nov. 7-9, 2016; Brighton, United Kingdom.