Pregnancy thyroid nodule Symptoms, diagnosis, treatment methods!

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Thyroid nodule in pregnancy

Pregnancy is associated with extensive hormonal and physiological changes. These changes can affect the function of the thyroid gland in different ways. One of the possible consequences of these changes is the occurrence or exacerbation of thyroid disorders, including thyroid nodule. A pregnant woman may have a thyroid nodule before pregnancy or may have this problem during pregnancy. Therefore, to maintain the health of the mother and the fetus, regular examination of the thyroid condition during this period is of particular importance.

Symptoms of pregnancy thyroid nodule

Symptoms of pregnancy thyroid nodule are the same as symptoms of thyroid nodule in normal people. However, physiological and hormonal changes during pregnancy may make interpretation of some symptoms and accurate diagnosis more difficult. The most important symptoms of pregnancy thyroid nodule include the following:

A lump or bump in the neck:

The main symptom is thyroid nodule. The thyroid nodule may be felt by touch or can only be detected in ultrasound.

Voice change or harshness:

Voice change is one of the possible symptoms of thyroid nodule. Large nodules can cause hoarseness, hoarseness, or change in pitch by pressing on the laryngeal nerve. Changes in voice may occur during pregnancy due to hormonal changes; But the presence of nodules can intensify these changes. Therefore, any abnormal voice changes during pregnancy should be checked by a doctor.

Pain in neck area:

Neck pain during pregnancy has various causes, thyroid nodule being one of them. This vague pain or pressure in the front of the neck can indicate the growth of the nodule or its pressure on the surrounding tissues.

Difficulty swallowing or breathing:

Very large thyroid nodules can cause swallowing and breathing problems by pressing on the trachea and esophagus. Although these symptoms are rare, they may indicate significant growth of the nodule and should be investigated immediately; especially if they are accompanied by other symptoms of thyroid nodule.

Diagnosis of thyroid nodule in pregnancy

Pregnancy does not affect thyroid nodule detection methods. In fact, tests to diagnose thyroid nodules in pregnancy are similar to other times. However, the interpretation of the test results will be slightly different according to the pregnancy conditions. The following are the most important methods used to diagnose thyroid nodules in pregnancy.

Physical examination

Neck examination is the first step to diagnose pregnancy thyroid nodule; But it cannot be a definitive diagnosis method alone. Also, physical examination of the neck is effective in detecting large and superficial nodules. During pregnancy, due to increased blood volume and hormonal changes, the thyroid gland may become slightly larger. This makes smaller or deeper nodules more difficult to detect by physical examination. Also, physical examination cannot determine whether the nodule is benign or malignant.

Physical examination of the neck can be done at any time of pregnancy; Especially at the end of the first trimester, bardrai is recommended. If there are suspicious symptoms or changes in the size of the thyroid gland, the physical examination may be repeated at subsequent visits. Neck examination is performed in a sitting or standing position. The doctor gently touches the neck and thyroid gland with his fingers to check the presence of any mass, bulge or change in the size of the thyroid gland. Usually, during the examination, the patient is asked to swallow his saliva.

Measurement of TSH level

Measuring TSH during this period is necessary and its results should be interpreted according to the trimester of pregnancy. In the first trimester of pregnancy, due to the stimulating effect of the hormone hCG, the level of TSH decreases in some women. In twin pregnancies, this decrease is observed more. A low level of TSH in the first trimester can indicate transient thyrotoxicosis of pregnancy, which may be accompanied by severe nausea and vomiting. The diagnosis of a functional nodule is made only if the TSH level is undetectable in the first trimester and remains the same in the second trimester. Undetectable means that the TSH (thyroid stimulating hormone) level in the blood test is so low that it cannot be measured by standard laboratory methods.

Toxic nodules are rare causes of hyperthyroidism in pregnancy. In case of suspicion of Graves' disease with non-functional nodule, anti-TSHR antibody test is necessary for diagnosis. TSH measurement is very important for thyroid nodules diagnosed in pregnancy. If the TSH level is less than 0.1 mIU/l and remains the same in the second trimester, it is considered a functional nodule during pregnancy.

sonography

Pre-existing nodules and nodules that appear during pregnancy may require different investigations and management. Since ultrasound is safe during pregnancy, it is used as the main method for diagnosing thyroid nodules in pregnancy. The EU-TIRADS classification, which is obtained from ultrasound results, determines the probability of benign and malignant nodules.

If the benign thyroid nodule was confirmed by ultrasound or biopsy before pregnancy and less than 2 years have passed since this diagnosis, there is no need for further investigations with ultrasound or biopsy. This means that the pregnant woman can be sure that the target thyroid nodule will not progress during pregnancy. However, careful palpation and examination of the neck at the end of the first trimester is recommended. In case of symptoms such as neck discomfort (especially when swallowing) or an increase in the volume of the nodule or the appearance of lymphadenopathy when palpating the neck, ultrasound should be performed as soon as possible.

Fine needle biopsy (FNAB)

In this method, using a thin needle, a sample of nodule cells is removed and examined in the laboratory. This method helps the doctor to make a definite diagnosis of malignancy or benign nodule. The decision to perform thyroid nodule biopsy in pregnancy should be made carefully and according to the specific conditions of each person by a specialist doctor. In general, doctors try to postpone thyroid nodule biopsy during pregnancy as much as possible. The reason for this is the existence of possible risks for the fetus and the mother. However, in some special cases, a biopsy is necessary; Including:

If the ultrasound shows that the nodule has very suspicious features (such as an irregular shape, an unclear border, or the presence of abnormal blood vessels), the doctor may recommend a biopsy.
In particular, if the nodule is EU-TIRADS category 5 (highly likely to be malignant) and is larger than 1 cm, or if the lymph nodes in the neck appear suspicious, a biopsy is necessary.
If the nodule causes problems such as difficulty swallowing, voice changes, or pain in the neck, the doctor may recommend a biopsy to determine the cause of these symptoms.

The time to perform a biopsy depends on the doctor's opinion and is determined according to the patient's condition and the stage of pregnancy.

Treatment of pregnancy thyroid nodule

Treatment of thyroid nodule in pregnancy depends on the condition of the patient, the number, size and whether the nodule is benign or malignant. Next, we introduce the methods of thyroid nodule treatment and explain which one is allowed in pregnancy.

Regular monitoring

Treatment of thyroid nodule during pregnancy often includes monitoring the nodule; Because most nodules are benign during this period. However, postpartum surveillance is also necessary, as hormonal changes of pregnancy can affect nodules. Postpartum consultation time should be determined with the agreement of the patient and based on the results of ultrasound or cell sampling. If the results indicate the possibility of malignancy, specialist consultation is recommended within 6 months after delivery. Overall, the decision on how to manage the nodule should be made with the active participation of the patient and based on the available evidence.

Toxic thyroid nodule

If there is a toxic thyroid nodule before pregnancy with a TSH level less than 0.1 mIU/L, treatment before pregnancy is a priority. In the first trimester of pregnancy, treatment with beta blockers can be started for symptomatic cases. Treatment with antithyroid drugs (ATD) is rarely necessary, and the decision to do so should be made after weighing the benefits and risks (ie, complications of hyperthyroidism during pregnancy versus complications of ATDs). The complications of ATDs with propylthiouracil (PTU) are less than other ATDs.

Since ATDs cross the placenta, if ATD treatment is continued until the second trimester (the fetal thyroid becomes active from week 18 of pregnancy), the goal of treatment is to maintain the mother's Free T4 in the high normal range to prevent hypothyroidism of the fetus. In these cases, ultrasound monitoring of the fetus from the 22nd week onwards should be done to check the symptoms of hypothyroidism of the fetus (goiter). Iodine supplements are not recommended in these conditions and the use of radioactive iodine is prohibited during pregnancy. In cases of symptomatic hyperthyroidism, symptomatic treatment (beta blockers) is prescribed as the first line of treatment, and treatment with ATDs at the minimum effective dose (free T4 target in the upper limit of normal) is necessary in rare cases.

Suppressive treatment

Suppressive treatment includes the use of levothyroxine (L-thyroxine). This treatment, which is used to reduce the size of benign thyroid nodules, is generally not recommended during pregnancy. Because in pregnancy, the risk of complications due to the increase of thyroid hormone in the blood (hyperthyroxinemia) is higher for the mother and the fetus. Therefore, the use of levothyroxine for the treatment of thyroid nodules during pregnancy is prohibited.

Destruction of thyroid nodules with heat (Thermal ablation)

This method involves the use of heat (for example, radio frequency) to destroy the tissue of the nodule. There is not enough information about the safety and side effects of this treatment method during pregnancy. In other words, it is not clear what effect this method has on the mother and fetus. Due to the lack of sufficient data and the contraindication of radiofrequency, doctors currently do not recommend thermal destruction of the thyroid during pregnancy.

Thyroid microcarcinoma (slow-growing cancerous thyroid nodule)

If small thyroid nodules with possible papillary carcinoma (microcarcinoma) are detected before or during pregnancy, active surveillance is recommended in the absence of lymph node involvement. Surgery during pregnancy is not recommended for these types of cancers, which are usually slow-growing. In case of cancer progression in pregnancy, the decision for surgery or continued monitoring should be made by a medical team consisting of several specialists.

Thyroid surgery

Thyroid surgery in pregnancy is not recommended for benign or stable nodules; But in cases of suspicious nodules or nodules that put pressure on the surrounding structures, it can be done after examination by a multi-specialty team. The best time for surgery is the second trimester of pregnancy; Because the first trimester increases the risk of miscarriage and the third trimester increases the risk of premature birth. Surgery is allowed at any stage of pregnancy if the mother's life is threatened.

Thyroid cancer without lymphatic metastasis or invasive features usually does not require immediate surgery in pregnancy; However, if the tumor progresses or there are aggressive features, surgery is recommended in the second trimester. If surgery is deemed necessary in the second or third trimester of pregnancy, it should be postponed until after delivery and follow-up after delivery should be carefully planned.

For consultation with Dr. Seyed Ahmad Fanai, thyroid surgeon and parathyroid and the best thyroid cancer surgeon with a history of more than 5000 successful thyroid surgeries, you can contact the numbers listed on the site. He, who is known as the Golden Paw thyroid surgeon, performs surgeries with the most up-to-date medical equipment to prevent the complications of thyroid surgery.

The effect of thyroid nodule in pregnancy

Thyroid nodule during pregnancy can have different effects. Benign nodules that do not disrupt normal thyroid function usually do not directly affect pregnancy. But functional nodules (hyperthyroidism or hypothyroidism) can cause serious complications. Untreated hyperthyroidism may lead to miscarriage, premature birth, pre-eclampsia and heart failure in the mother. Untreated hypothyroidism can also cause miscarriage, premature birth, neural development problems in the fetus and anemia in the mother. Thyroid cancer is rare in pregnancy; But if there is, it needs careful management.

Last word

During pregnancy, several factors can cause the development and growth of benign or malignant thyroid nodules. Iodine deficiency, the stimulating effect of hCG hormone on TSH receptors and the increase of TSH and estrogen are among these factors. Proper diagnosis and management of thyroid nodule before and during pregnancy is very important. Pregnant women with thyroid nodules should be under the supervision of an endocrinologist and gynecologist and perform regular thyroid tests to evaluate the function of the gland and adjust the dose of thyroid medications.

1404-03-11

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