Hypothyroidism During Pregnancy

by Dr. Michele Brown OB/GYN

Here's What You'll Find Below:  • Overview
  • Hypothyroidism in pregnancy
  • Dangers to mother and fetus
  • Causes of hypothyroidism
  • How is it diagnosed?
  • What is the treatment?
  • Subclinical hypothyroidism
How does hypothyroidism affect your baby?
  • Summing it up

feeling sickLet's pretend we have a 26-year-old, newly-pregnant woman sitting on the exam table in her obstetrician's office. While she is excited about her pregnancy, she is verbal and is telling her physician about the terrible nausea and vomiting, anxiety, difficulty sleeping, and general fatigue.

The obstetrician can easily see that she seems to be suffering the normal symptoms of pregnancy but is also a bit worried that it may be something else. Even if nausea and vomiting occur in 50–80% of all pregnant women, especially between the 5th and 13th week, a good obstetrician will go a bit further to make sure it is not something more serious before suggesting a medication, or a supplement, to reduce the symptoms of nausea and vomiting.

Is it possible that this woman is experiencing something more severe than the normal, early pregnancy symptoms? Could it be hypothyroidism?

Quick Review

One of the great masqueraders for pregnant women is thyroid disease. Many of the symptoms that women experience in the early stages of pregnancy are the exact symptoms that occur with thyroid problems. Women will commonly experience fatigue, weight gain, constipation, insomnia, and lethargy.

Health care providers will often reassure patients that this is normal and these symptoms are due to the hormonal and physiological changes that one expects with the early stages of a healthy pregnancy. However, one must be on the alert that these same symptoms could be representative of a much more serious underlying problem; one that could have major, negative ramifications on the pregnancy and the newborn infant.

Left undiagnosed and untreated, hypothyroidism (low thyroid hormone) could result in serious, high-risk conditions during the pregnancy. Prematurity, preeclampsia, placental separation (abruption), and/or serious consequences in the child such as congenital cretinism (mental retardation, deafness, muteness).

This article will focus only on hy-PO-thyroidism. (when you have too little thyroid hormone) and its effects on pregnancy.

Symptoms of hypothyroidism often mimic a normal early pregnancy, such as weight gain and lethargy with a decrease in exercise ability. Hypothyroidism is defined as the inability to manufacture thyroid hormone by the thyroid gland. Missing this diagnosis can have grave, irreversible neurological consequences for the fetus.

Hypothyroidism in Pregnancy

How often does hypothyroidism occur in pregnancy?

Hypothyroidism occurs in .1 to .3% of pregnancies. It can be associated with other autoimmune disorders such as diabetes. It is often a cause of difficulty in conceiving since women with this condition have difficulty ovulating.

What are the symptoms of hypothyroidism?

intellectual slowness
voice changes (hoarseness)
lethargy or decrease in exercise capacity
prolonged relaxation of deep tendon reflexes
concentration difficulties