What causes low thyroid stimulating hormone during pregnancy?

Regular thyroid examination is a necessary check-up item for pregnant women, and it is also an important indicator for monitoring the healthy development of the fetus at all times. Some women will experience high levels of thyroid stimulating hormone during pregnancy, which is also called hypothyroidism and needs to be monitored and regulated. Some women also experience low levels of thyroid stimulating hormone during pregnancy. So, what is going on?

Causes of low TSH in early pregnancy:

1. Expectant mothers may be unfamiliar with thyroid-stimulating hormone before, but they are very familiar with the word thyroid. The thyroid gland is an important endocrine organ in the human body. The thyroid hormone it secretes can promote tissue metabolism and development, and also plays an important role in increasing the excitability of the nervous system. Thyroid hormone is regulated by thyroid-stimulating hormone.

2. After a woman becomes pregnant, her body's endocrine system undergoes many adjustments to adapt to the needs of pregnancy, including thyroid hormone. Affected by the sharply increased HCG levels in early pregnancy, the activity of the thyroid gland will also increase accordingly, resulting in an increased trend in thyroid hormone levels in pregnant women. At this time, the "negative feedback" mechanism of thyroid hormone will come into play to inhibit the secretion of thyroid-stimulating hormone, thereby maintaining the balance of thyroid hormone levels in the body. This is why there is a downward arrow (low) on the thyroid-stimulating hormone item on the checkup report that expectant mothers receive in early pregnancy. This phenomenon is very normal. Generally, TSH levels will return to normal in the second and third trimesters of pregnancy.

3. Low thyroid stimulating hormone caused by disease. However, if the thyroid hormone in the pregnant woman's body is elevated due to disease, which in turn reduces the thyroid stimulating hormone level, it needs to be taken seriously. It is necessary to be careful to prevent the occurrence of hyperthyroidism during pregnancy. If not treated in time, it may cause pregnant women to suffer from heart failure, preeclampsia, thyroid crisis, miscarriage, premature birth, low birth weight and other diseases. However, the diagnosis of hyperthyroidism during pregnancy cannot be made solely by the low level of thyroid-stimulating hormone, but requires a comprehensive diagnosis through other examinations.