The superficial location of the thyroid gland allows you to examine the organ with your hands. Ultrasound of the thyroid gland during pregnancy can be done, but the study does not make sense without determining TSH, and examination by an endocrinologist. That is, an ultrasound examination method is prescribed to clarify the diagnosis if the endocrinologist sees an increase or identifies nodes on palpation.
The normal volume of the thyroid gland in women is up to 18 cm³. A knot is a formation that is larger than 1 cm in diameter. If such a node is found on ultrasound, then it is advisable to puncture it and make sure that the process is not oncological.
Our country is in an endemic zone: almost everyone has mild and moderate iodine deficiency. Therefore, if the thyroid hormones are normal, then usually nothing is done with such nodes.
Changes in thyroid hormones during pregnancy
During pregnancy, TSH levels decrease. The norm for a “non-pregnant” organism is 0.4-4 mU . In pregnant women, the TSH rate is lower:
- in the first trimester – <2.5 mU ;
- in the second and third trimester – <3 mU .
Why is there a decrease in thyroid-stimulating hormone during pregnancy?
In the early stages of pregnancy, hCG increases in the body, in addition to the function of maintaining pregnancy, it acts on the thyroid gland as a stimulant, that is, it has a similar effect on the thyroid gland as TSH. Accordingly, the thyroid gland works more actively, releases more hormones into the bloodstream. In response, the pituitary gland realizes that there are more thyroid hormones and less stimulating TSH is released. This situation occurs during normal physiological pregnancy.
The correct functioning of the thyroid gland during pregnancy has an effect on the development and laying of the baby’s mental abilities and so that various malformations do not arise.
The hormonal background during pregnancy changes, but it does not change exactly the same. There are cases when chorionic gonadotropin very strongly stimulates the thyroid gland and the TSH level can be less than 0.1 mU . In such a situation, if there is no severe toxicosis , pregnancy develops normally, there is no pronounced tachycardia (more than 140 beats per minute), this may be gestational hyperthyroidism that does not require treatment. But you always need to be wary of true thyrotoxicosis. If the TSH level is very low and there are complaints, then you need to take a blood test for antibodies to TSH receptors, it is called AT-p-TSH. If these antibodies are not detected, then the prohibitive decrease in TSH is associated with pregnancy, and not with diffuse toxic goiter.