Thyroid hormones are needed for foetal development, so you may wonder if you can have a successful pregnancy with hypothyroidism or if having hypothyroidism can cause problems during pregnancy.
The thyroid gland is located in the neck and its function is to regulate, by means of the thyroid hormones, a huge number of processes that make up the body’s metabolism: how we use energy, how we regulate temperature, and so on.
Hypothyroidism (having a lack of thyroid hormones) is a very common problem. The gland can also be disrupted during pregnancy without pre-pregnancy hypothyroidism.
Symptoms of thyroid gland abnormalities in pregnancy
During pregnancy, changes in thyroid gland function are common due to hormonal fluctuations. Both oestrogen and the human chorionic gonadotropin (hCG) hormone, which is responsible for positive pregnancy tests, influence the thyroid gland and can cause the thyroid gland to be disrupted during pregnancy.
Given the different types of disorders, it is useful to separate the characteristic symptoms of gland disorders into two types.
Hypothyroidism pregnant
Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormone. Symptoms of gestational hypothyroidism, that is, during pregnancy, may include:
- General fatigue and weakness.
- Weight gain for no apparent reason.
- Feeling excessively cold.
- Constipation.
- Dry skin and brittle hair.
- Swelling of the face and limbs.
- Bradycardia (slower than normal heartbeat).
- Difficulties with concentration and memory.
- Depression or mood swings.
Hyperthyroidism in pregnancy
When the thyroid gland produces an excess of thyroid hormone, this is known as hyperthyroidism. Symptoms of hyperthyroidism during pregnancy may include:
- Palpitations or tachycardia (fast heartbeat).
- Feelings of nervousness or anxiety.
- Increased sweating.
- Weight loss for no apparent reason.
- Trembling hands.
- Fatigue and muscle weakness.
- Irritability and mood swings.
Complications arising from hypothyroidism in pregnancy
Untreated thyroid disorders during pregnancy can lead to major complications for both mother and baby:
- Miscarriage: especially during the first three months of pregnancy.
- Pre-eclampsia: Women with hypothyroidism are at a greater risk of developing pre-eclampsia, which can lead to severe complications.
- Preterm birth.
- Low birth weight and delayed foetal development.
- Congenital hypothyroidism: if hypothyroidism is not properly treated during pregnancy, it can increase the risk of the baby being born with congenital hypothyroidism, which requires immediate treatment after birth.
- It can even lead to breastfeeding problems.
So, if there is a problem before pregnancy, it should be monitored prior to pregnancy in case some of the consequences of a thyroid problem in pregnancy that we have seen, occur. And if it appears when you are already pregnant, it is important to monitor it throughout the pregnancy.
What is the ideal TSH for pregnancy?
The normal reference range for TSH levels in non-pregnant women is usually 0.4 to 4.0 mIU/L. However, during pregnancy, normal TSH levels are thought to be lower. We can say that the normal range in the first trimester is usually between 0.5 to 2.5 mIU/L. And in the second and third trimester, around 0.5 to 3.0 mIU/L.
However, it is important to remember that each pregnancy is unique and that TSH values must be interpreted in conjunction with other parameters such as T4 (thyroxine) levels.
Treating hypothyroidism in pregnancy
Even if you have hypothyroidism, you can still get pregnant. Treatment for hypothyroidism is based on providing a woman with the missing hormone. This is done using a synthetic thyroid hormone called levothyroxine, which is identical to the hormone produced naturally in the body and helps correct low blood levels. Thyroid hormone doses need to be adjusted several times during pregnancy, so regular blood tests will be done to monitor levels and ensure that everything is going smoothly.
Along with this hormone, it is advisable to modulate the immune system through rest, physical activity or diet, as we saw when we talked about hypothyroidism and fertility. After all, pregnancy in a woman with hypothyroidism requires close monitoring by both the obstetrician and the endocrinologist, but there is no reason why it should not have a happy ending.
