Thyroid can raise the risk of pregnancy complications

Health Services


Thyroid hormones are essential in the regulation of early development and play a key role in the maintenance of a normal pregnancy and in the development of the foetus.


As soon as your pregnancy is confirmed, you will be advised to take a thyroid test. (Source: Getty Images)

By Dr Mini Salunkhe

Thyroid conditions can, for the most part, be easily managed in day-to-day life if treated with the right medications. However, the risks of low or high thyroid hormone levels become much more apparent during pregnancy. It is important that thyroid diseases—hyperthyroidism and hypothyroidism— are treated and attended during pregnancy.

What is thyroid?

Thyroid is an “organ” located in the front of your neck that releases hormones that regulate your metabolism (the way your body uses energy), heart and nervous system, weight, body temperature, and many other processes in the body. It forms an integral part of the endocrine system which does the vital job of producing hormones for your body. The thyroid gland produces two major hormones, T3 and T4. Hormones created by the thyroid control your body’s metabolism and many other vital bodily functions like weight, brain development, breathing functions, and body temperature and cholesterol levels. It is important to monitor thyroid levels in pregnancy since it can have a telling impact on the foetus including the neuron intellectual abilities of the baby.


Thyroid and pregnancy

A thyroid problem when pregnant is common when a woman is in her prime childbearing age, but if it is not diagnosed on time, its impact can extend well beyond pregnancy. While hyperthyroidism is caused due to high levels of hormones in the blood, hypothyroidism is caused due to decreased levels of thyroid hormones in the blood.

As soon as your pregnancy is confirmed by your doctor, you will be advised by the doctor to take a thyroid test. You may also have to take one if you are planning to conceive. Although thyroid during pregnancy is a common condition, there is a possibility of confusing it with other regular pregnancy symptoms due to its similarities. Symptoms like weight gain, feeling tired, getting moody or forgetful and even swelling up are common to pregnancy and thyroid condition.

Symptoms of hyperthyroidism during pregnancy

  • Fatigue
  • Nausea
  • Vomiting
  • Fast heart rate
  • Change in appetite
  • Growth of thyroid levels and thyroid size

Symptoms of hypothyroidisim during pregnancy

  • Swollen face
  • Fatigue
  • Intolerance to cold
  • Weight gain
  • Lower concentration levels
  • Skin tightening
  • Abdominal discomfort

When pregnancy is compounded by endocrine disorders such as hypothyroidism, the potential for maternal and foetal adverse outcomes can be immense. Prompt diagnosis and treatment of hypothyroidism in pregnancy is very essential. Subclinical hypothyroidism also needs to be detected and treated to prevent adverse outcomes, especially maternal. Since women with hypothyroidism during pregnancy, especially of the autoimmune variety might have a flare up of the disorder post-partum, or might continue to require thyroxine replacement post-partum, adequate follow-up is mandatory.


While targeted case finding is generally practiced, recent evidence seems to indicate that universal screening might be a better option. In conclusion, routine screening, early confirmation of diagnosis and prompt treatment is the key to overcome any problems related to thyroid and pregnancy.

Women who have been diagnosed with hyperthyroidism before their pregnancy and with a family history of this disorder are most likely to experience this condition during their pregnancy. On the other hand, women who have a past family history of hypothyroidism or have been diagnosed with this condition in the past are at risk of developing this condition during pregnancy.

Allied with regular post-partum follow up, is required to ensure favourable maternal and foetal outcomes. Hypothyroidism is widely prevalent in pregnant women and the rate of detection, especially in a developing country like India, has not kept pace with the magnitude of the problem.

Since hypothyroidism is easily treated, timely detection and treatment of the disorder could reduce the burden of adverse foetal and maternal outcomes, which are very commonly encountered.

Common tests for diagnosis of thyroid

It is possible to diagnose hyperthyroidism in pregnant women through the following tests:

  • TSH test
  • T3 & T4 test
  • TSI test

How does pregnancy affect thyroid functions?

During pregnancy, two hormones, estrogen and human chorionic gonadotropin (hCG) are responsible for enhancing your thyroid levels. These thyroid hormones play a vital role when you are pregnant, both in the baby’s brain and nervous system development and your health.

The placenta makes hCG, which is similar to TSH and stimulates the thyroid to create more hormones. Increase in oestrogen levels produces thyroid-binding globulin, a protein that helps the thyroid hormone to travel in blood. In the first trimester, your baby is dependent on you for its thyroid hormone needs, which comes through the placenta. This will go on until the 12th week, after which the baby’s thyroid will begin functioning on its own.

Doctors already know that low thyroid hormone levels in pregnant women are linked to lower child IQ scores as well as other risks to the foetus. Based on current evidence, treatment guidelines from the American Thyroid Association in 2011 and the Endocrine Society in 2012 recommend medical treatment of pregnant women with subclinical hypothyroidism. In this mild form of thyroid disease, there is an increased amount of thyroid-stimulating hormone (TSH), the substance that spurs production of and maintains adequate amounts of the thyroid hormones, T3 and T4, which control how your body uses energy.

There is consensus to treat subclinical hypothyroidism because it is generally believed that the potential benefits of treatment outweigh the potential risks of over-treatment.

Increased levals of hyperthyroidism can lead to preeclampsia, premature birth, miscarriage and sudden worsening of hyperthyroid symptoms. A newborn can suffer from rapid heart rate leading to heart failure, poor weight gain, low birth weight, irritability and enlarged thyroid causing breathlessness.

How to avoid complications of thyroid

During pregnancy, if an expectant mother is diagnosed with thyroid, it is important to follow the tips below:

Stay away from diets that recommend starvation for long periods. Fasting results in a huge reduction of T3 levels which enhances metabolism.
Quit smoking if you have been smoking prior or during the time of confirmation of your pregnancy. Studies suggest that smoking increases the risk of hypothyroidism.
Thyroid hormones are essential in the regulation of early development and play a key role in the maintenance of a normal pregnancy and in the development of the foetus.

(The writer is Consultant-Obstetrician and Gynaecologist, Cloudnine Group of Hospitals, Kalyani Nagar, Pune.)

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