Thyroid Conditions during Pregnancy

The thyroid is a tiny, butterfly-shaped gland in your neck. A gland is an organ that creates substances that assist your body in functioning. The thyroid produces hormones (chemicals) which play an essential role in your health.

Dr. Mukesh Mahajan Created on 28th Dec, 20

The thyroid is a tiny, butterfly-shaped gland in your neck. A gland is an organ that creates substances that assist your body in functioning. The thyroid produces hormones (chemicals) that play an essential role in your health.


Sometimes the thyroid gland creates these hormones in excess or fewer amounts. When this occurs, you have a thyroid disorder.


Some women have a thyroid disorder that starts before their pregnancy (also called a pre-existing condition). Others might develop a thyroid disorder during pregnancy or immediately after delivery.


With treatment, a thyroid disorder may not create any problems during pregnancy. However, thyroid conditions that go untreated can cause troubles for you and your baby during pregnancy or after birth.


What are the Types of Thyroid Conditions?

There are two main types of thyroid conditions:


Hyperthyroidism (“hyper” meaning too much)


When your thyroid is overactive and makes too much thyroid hormone, it causes hyperthyroidism. It can cause many of your body’s activities to speed up.


Hyperthyroidism during pregnancy occurs due to an autoimmune disorder called Graves’ disease. Autoimmune disorders happen when antibodies (cells in the body that fight off foreign bacteria) attack your healthy tissue.

If you suffer from Graves’ disease, your immune system creates antibodies. This causes your thyroid to make excess thyroid hormone.

In a few cases, hyperthyroidism can cause a severe form of morning sickness. It is excessive nausea and vomiting during pregnancy.

Also, in some cases, hyperthyroidism can happen due to thyroid nodules. These are lumps in your thyroid that create excess thyroid hormone.


Symptoms of hyperthyroidism during pregnancy include:

  • Irregular heartbeat
  • Nervousness
  • Severe nausea or vomiting
  • The slight tremor in my hands
  • Sleep deprivation
  • Weight loss or low weight gain beyond the usual pregnancy


Hypothyroidism (“hypo” meaning too little or not enough)


When the thyroid is underactive and does not make enough thyroid hormones, it is known as hypothyroidism. In this condition, many of your body’s functions become slow.

Hypothyroidism during pregnancy is due to an autoimmune disorder called Hashimoto’s disease. When you suffer from Hashimoto’s disease, your immune system creates antibodies that attack your thyroid. It damages your thyroid so it cannot make thyroid hormones.

Symptoms of hypothyroidism during pregnancy may include:

  • Constipation
  • Weight gain, beyond the usual pregnancy weight
  • Extreme tiredness
  • Difficulty in concentrating
  • Sensitivity to cold temperatures
  • Muscle cramps


If you have a thyroid disorder during pregnancy, treatment can assist you to have a healthy pregnancy and a healthy baby.


Risk of Thyroid Condition during Pregnancy

You are at a higher risk for a thyroid condition during pregnancy than at other times if:

  • You are getting treatment for a thyroid problem, or you have thyroid nodules or a goitre
  • You had a thyroid condition in the past (including after giving birth), or you had a baby who was suffering from a thyroid condition
  • You have an autoimmune disorder, or you have a genetic history of autoimmune thyroid disorders. This includes Graves’ disease or Hashimoto’s disease.
  • You have type 1 diabetes; it is pre-existing diabetes, which means you have it before you get pregnant.


If you had a thyroid condition before or think you may be at risk of having a thyroid condition, ask your doctor about testing.


What can Hyperthyroidism affect Pregnancy?

Some of the effects of hyperthyroidism for women and babies are mentioned below.

Problems for women:

  • Preeclampsia: It is a severe blood pressure condition that occurs after the 20th week of pregnancy or after birth
  • Pulmonary hypertension: A kind of high blood pressure which occurs in arteries in your lungs or the right side of your heart.
  • Placental abruption: It is a severe condition in which the placenta detaches from the uterus wall before birth. The placenta grows inside your uterus (womb) and gives the baby food and oxygen through the umbilical cord.
  • Heart failure: It happens when your heart cannot pump enough blood to your body.
  • Thyroid storm: It happens when your symptoms suddenly worsen. Thyroid storm is rare but life-threatening during pregnancy. Pregnant women who suffer from thyroid storm are at a high chance of heart failure.


Problems for babies:

  • Premature birth (before 37 weeks of pregnancy)
  • Goitre
  • Low birth weight (less than 5 pounds, 8 ounces)
  • Thyroid problems
  • Miscarriage or stillbirth


How can Hypothyroidism affect Pregnancy?

Untreated hypothyroidism can cause problems for women and babies during pregnancy or after birth.


Problems for women:

  • Anaemia (lack of red blood cells)
  • Gestational hypertension (high blood pressure)
  • Preeclampsia
  • Placental abruption
  • Postpartum haemorrhage (also called PPH)(heavy bleeding )
  • Myxedema (severe untreated hypothyroidism causes coma and death)
  • Heart failure (a rare condition)


Problems for babies:

  • Infantile myxedema (dwarfism, intellectual disabilities and other problems)
  • Low birth weight
  • Problems with growth and brain and nervous system development
  • Thyroid problems
  • Miscarriage or stillbirth


Medicines used to treat thyroid problems during pregnancy are safe for your baby. These medicines can help you maintain the level of thyroid hormones in your body.

If you are taking medicine for a thyroid problem before pregnancy, talk to your doctor before you get pregnant.

Your doctor may adjust or change your medicine to make sure your baby is safe. If you are already taking medication for your thyroid condition when you get pregnant, keep taking it and talk to your doctor about it as soon as possible.