Need early screening for hypothyroidism in pregnant women

This is an automatically translated article.

This article is professionally consulted by Master, Doctor Vu Thi Duyen - Department of Medical Examination & Internal Medicine - Vinmec Hai Phong International General Hospital.
Currently, Vietnam is located in an iodine-deficient region, especially in mountainous areas, so pregnant women have a very high risk of thyroid disease. One of the diseases to be concerned about is hypothyroidism. If not detected and treated promptly, it can cause dangerous complications for both mother and fetus.

1. Importance of thyroid hormone for the fetus

The thyroid is an endocrine gland, butterfly-shaped, usually located in the front, under the neck. The function of the thyroid gland is to synthesize thyroid hormone, which is secreted into the blood and into the tissues of the body. Thyroid hormones help the body use energy, stay hydrated, and keep the brain, heart, and other organs functioning properly.
During pregnancy, the mother's thyroid gland has to increase activity to provide thyroid hormone for the fetus, especially in the first 3 months of pregnancy. Thyroxin hormone is essential for the development of the brain and central nervous system of the fetus. In the first 3 months of pregnancy, the thyroid gland of the fetus is not active, which means it has not yet synthesized the hormone, so the fetus must use thyroxine completely from the mother. Then, in the following months, thyroxine is partially obtained from the mother and partly synthesized. Thyroxin is transported to the fetal brain and converted to T3 involved in early development and maturation of the brain and central nervous system. Therefore, maternal hypothyroidism during pregnancy will greatly affect the fetus. If the mother is not detected and treated promptly, the child may be born with severe hypothyroidism, thereby affecting the child's development, especially intellectual development, leading to cretinism.

2. Common causes of hypothyroidism in pregnancy

There are many causes of hypothyroidism and all can occur in pregnant women. The most common cause is chronic thyroiditis, an autoimmune thyroid disease known as Hashimoto's thyroiditis (named after the Japanese doctor who discovered this disease). ). Hashimoto's disease can be present before pregnancy (but because it is a chronic disease, it progresses slowly, so many people can't detect it and miss it) or it can appear for the first time during pregnancy.
Other causes of hypothyroidism may be due to thyroidectomy due to tumors or nodules or radioactive iodine treatment (I131) or because of treatment basedow with synthetic antithyroid drugs too high doses not according to periodic follow-up and re-examination.
Women at high risk for hypothyroidism during pregnancy include:
Have been or are being treated for hyperthyroidism (with synthetic antithyroid drugs, surgery, radioactive iodine). There is a strong family history of thyroid disease. People with large goiters, people who have had thyroiditis or hypothyroidism in a previous pregnancy...

3. Consequences of hypothyroidism during pregnancy

3.1. If left untreated or inadequately treated, the mother can develop all of the classic complications of hypothyroidism such as anemia, muscle weakness, congestive heart failure, common pericardial effusion, sluggishness, constipation...
In addition, pregnant women are also at risk of other obstetric-related complications such as pre-eclampsia, low birth weight and heavy postpartum bleeding. These complications tend to be common in women with severe hypothyroidism, and most cases of mild hypothyroidism may be asymptomatic or very mild and difficult to detect.
3.2. With the fetus The fetal thyroid gland is only formed and begins to work at the 10th - 12th week of pregnancy, this means that during the first 12 weeks (the first 3 months), the fetus depends entirely on the source of the fetus. thyroid hormone from the mother. So if the mother has hypothyroidism, the baby will also have hypothyroidism.
Thyroid hormone has an extremely important role in the division, formation of organs as well as brain development of children. Children with congenital hypothyroidism can have severe abnormalities in both intellectual and physical development if not detected and treated promptly.
Currently, in some major hospitals, there are screening programs for neonatal thyroid disease, the results show that most of these abnormalities are preventable if detected and treated early with supplementation thyroid hormone shortly after birth.
If the mother has untreated hypothyroidism during pregnancy, the fetus is at increased risk:
The miscarriage rate doubles. Perinatal mortality is about 20%. Birth defects increased by 20%. Nearly 1 in 2 babies are born with psychomotor retardation. In addition, recent research shows that during pregnancy, mothers with fetal hypothyroidism are more likely to have reduced attention span, reduced learning ability, and decreased intelligence quotient (IQ). scores compared with children in the control group of the same age (8 years).

4. Who needs early detection of hypothyroidism during pregnancy?

Having a history of thyroidectomy, head and neck radiation treatment, radioactive iodine treatment. Have autoimmune diseases, family history of autoimmune diseases (type 1 diabetes, rheumatoid arthritis0). Have a history of thyroid disease. Being in an iodine-deficient area Have a goiter Being treated for hypothyroidism. With these subjects, when preparing for pregnancy, it is necessary to have TSH and FT4 tests to evaluate thyroid function and during pregnancy, it is also necessary to monitor regularly.
The package of screening and screening for thyroid diseases of Vinmec International General Hospital helps: Check thyroid function. Screening & early detection of common thyroid diseases such as simple goiter, hyperthyroidism, hypothyroidism, thyroiditis, thyroid nodules, thyroid cancer, etc. appropriate and timely treatment.
It is very good to diagnose and screen for thyroid disease in pregnant women at the earliest during pregnancy and should be done early. It is best that before planning a pregnancy, mothers need to be screened for thyroid disease to ensure the best health for both mother and fetus.

Please dial HOTLINE for more information or register for an appointment HERE. Download MyVinmec app to make appointments faster and to manage your bookings easily.