Hyperthyroidism with pregnancy

Introduction to hyperthyroidism combined with pregnancy The thyroid gland is one of the most important endocrine organs in the human body. Thyroid hormone plays an important role in reproduction, growth and development and metabolism of various system organs. Hyperthyroidism is the most common endocrine disease, which is more common in female patients. The ratio of male to female is 1:4-6. Among them, women of childbearing age of 20 to 40 years old are more common. Among the endocrine diseases of pregnant women, thyroid disease ranks second only to diabetes. The data show that the incidence of hyperthyroidism combined with pregnancy is 0.5% to 2%. The pregnancy rate of hyperthyroidism is as high as 26% and the premature rate is 15%. basic knowledge The proportion of illness: 0.001% Susceptible population: women of childbearing age between 20 and 40 are more common Mode of infection: non-infectious Complications: abortion, premature delivery, anemia, pregnancy-induced hypertension, placental abruption, congestive heart failure, diabetes, premature infant, fetal distress, neonatal asphyxia

Hyperthyroidism combined with pregnancy etiology

(1) Causes of the disease

Graves disease (referred to as GD), also known as toxic diffuse goiter or Basedow disease, is an organ-specific autoimmune disease with increased secretion of thyroid hormone (TH). The clinical manifestations are not limited to the thyroid gland, but a multi-system Syndrome, including: high metabolic syndrome, diffuse goiter, eye signs, skin lesions and thyroid extremity.

Subacute thyroiditis, also known as viral thyroiditis, DeQuervain thyroiditis, granulomatous thyroiditis thyroid anatomy or giant cell thyroiditis, was first reported by DeQuervain in 1904. The disease has gradually increased in recent years, the clinical changes are complex, there may be misdiagnosis and missed diagnosis, and easy to relapse, leading to a decline in health, but most patients can be cured. The disease may be characterized by the onset of the population due to seasonal or viral epidemics.

Thyroid cancer is the most common thyroid malignancy, accounting for about 1% of systemic malignancies. Except for medullary carcinoma, most thyroid cancers originate from follicular epithelial cells.

1. The most common cause of hyperthyroidism during pregnancy is

(1) Diffuse toxic goiter.

(2) Chronic lymphatic thyroiditis (Hashimotos disease Hashimoto's disease).

(3) Toxic nodular goiter.

(4) Toxicity of single thyroid adenoma.

2. The causes of rare hyperthyroidism are

(1) Trophoblastic disease.

(2) ovarian teratoma contains thyroid components.

(3) Iodomethyl hydrazine and the like.

(4) hyperemesis in pregnancy.

(5) iatrogenic hyperthyroidism.

Graves disease, accounting for more than 85% of all patients with hyperthyroidism; multiple toxic nodular goiter accounted for 10% of the report; toxic single thyroid adenoma accounted for 1/181 of the patient; subacute thyroiditis 2/182; Source hyperthyroidism refers to the excessive use of thyroid hormone in the replacement therapy, only TSH is reduced, FT4I and FT4 are normal, and most cases have no clinical symptoms. As long as the amount of thyroid hormone is reduced, the thyroid function index can return to normal after 4 to 6 weeks.

(two) pathogenesis

The exact mechanism is unknown. The thyroid gland during pregnancy may have the following changes: the increase of maternal blood volume during pregnancy may cause the expansion of thyroid hormone pool and the dilution of serum iodine. At the same time, due to the increase of renal blood flow, glomerular filtration iodine increases in serum. The decrease of inorganic iodine concentration, the so-called "iodine starvation" state, makes the thyroid gland compensatory. The maternal thyroid function during pregnancy is affected by some hormones in the placenta and hypothalamus-pituitary. The earliest and obvious change is serum thyroid hormone binding. The increase of globulin level, followed by TT3, TT4 increased; serum free T3, T4 is mostly normal, early can be slightly increased, slightly decreased at the end of pregnancy; thyroid stimulating hormone (TSH) increased in early pregnancy, when the placenta produced When human chorionic gonadotropin (hCG) is elevated, TSH is inhibited and decreased to a lower level. A small proportion of pregnant women may have TSH below the normal level, and about 20% of pregnant women can detect anti-thyroid autoantibodies.

Hyperthyroidism combined with pregnancy prevention

1. Banned iodine during pregnancy in non-iodine-deficient areas, except before thyroid surgery or during thyroid crisis.

2. Breastfeeding women and newborns should also avoid contact with iodine, such as the use of iodine disinfectant treatment, may also lead to neonatal hypothyroidism.

Hyperthyroidism combined with pregnancy complications Complications, abortion, premature anaemia, pregnancy-induced hypertension, placental abruption, congestive heart failure, diabetes, premature infant, fetal distress, neonatal asphyxia

The prognosis of the mother and the fetus is directly related to the degree of control of the hyperthyroidism. If the patient has a history of hyperthyroidism in the past, pre-pregnancy hyperthyroidism, and has been well controlled, or early detection of hyperthyroidism for reasonable treatment, the general mother and newborn have a good prognosis. If the mother is still in hyperthyroidism until the second trimester, the complications of the mother and the fetus or newborn are significantly increased. The complications of the mother and the fetus and the newborn are as follows:

Mother's complications: miscarriage, premature delivery, anemia, pregnancy-induced hypertension, placental abruption, congestive heart failure, hyperthyroidism, intermittent infection, type I diabetes.

Fetal and neonatal complications: premature infants, stillbirth, stillbirth, malformation, FGR, small for gestation age (SGA), fetal distress, neonatal asphyxia, fetal and/or neonatal hypothyroidism, Fetus and/or neonatal hyperthyroidism.

Hyperthyroidism combined with pregnancy symptoms Common symptoms Shortness of breath thinning corneal ulcer tachycardia Painful alopecia Weight gain Trembling pulse pressure difference Large thyroid function

1. Pregnant women have physiological enlargement of the thyroid gland, and are also easily confused with the early hyperthyroidism. The thyroid physiology is generally less than 20%. The thyroid gland is diffusely enlarged in Graves' disease. It can be 2 to 4 times normal. Symmetry, a leaf can be slightly larger, the gland texture can be soft to hard, occasionally tender, the surface of the gland is smooth, can touch the tremor, and hear the vascular noise that continues to go back and forth, pregnant women are afraid of heat, sweating, physics Examination revealed that the skin was flushed, the skin temperature was elevated, the skin was moist and sweaty, the skin of the hands and face was shiny and shiny, and occasionally the anthurium and telangiectasia were manifested. The patient complained of hair loss, and the hair was found to be fine and brittle, with 5% of Graves' disease. The patient has sputum mucus edema, or invasive skin disease, and there is concave edema when combined with pregnancy-induced hypertension syndrome.

2. Eye signs are the most common, and invasive eye diseases account for 30% to 50%, which is unique to Graves' disease. The eyeballs are bright and prominent, also called hyperthyroidism. "The eye is retracted, especially when the patient looks down. The upper eyelid retracts and lags. When the eye is closed downward, a clear scleral border can be seen between the eyelid margins. The invasive eye disease of Graves disease is very special. Even if the hyperthyroidism has been treated for a period of time, the eye can continue to exist, and the severe hyperthyroidism is not much. See, the symptoms of the eye include: eye irritation, photophobia, tearing and eye discomfort, especially after watching TV and reading. When the disease is serious, it is not clear, double vision, examination can reveal the patient's gaze, periorbital edema Conjunctival congestion and edema, eyelids can not be closed, and some corneal ulcers will occur. In a few cases, eyeball insufficiency occurs, optic disc edema.

3. The muscles of the limbs are fatigued and weak. When changing the position, you need the support of your hands. The pregnant woman feels flustered and short on the stairs.

4. Cardiovascular system changes are prominent features of thyrotoxicosis, peripheral resistance decreases, cardiac output increases, tachycardia, heart rate exceeds 90 beats/min at rest, pulse pressure difference is large, pulse pressure difference is >6.7kPa (>50mmHg ), physical examination shows that the heart beats diffuse and powerful, the heart may expand, the apex can smell the systolic hair-like noise, the heart sounds bright, 10% of patients with thyrotoxicosis have atrial fibrillation, can occur in women who did not have heart disease in the past, 1991 Easterling et al. studied 6 cases of hyperthyroidism with pregnancy. The hemodynamic changes were observed in the gestational period from the 12th week of pregnancy. The cardiac output was increased by 65%, the total peripheral resistance was reduced by 35%, and the heart rate was increased by 21%. %, so they proposed that the huge changes in hemodynamics of pregnant women with hyperthyroidism can not be ignored, even if the thyroid function is corrected and maintained normal, hemodynamic changes will continue for some time.

5. Digestive system and metabolic changes, patients complain of heat, weight loss, good appetite, eating a lot of cases, check the weight of pregnant women can not increase with gestational weeks, individual severe weight does not grow or even decline, intestinal peristalsis increases, stool is soft, The number of times has increased.

6. Abnormal performance of the nervous system includes irritability, irritability, difficulty in getting along with others, crying and laughing; concentration time is shortened, although feeling tired and weak, still can not control the action, excessive activity; trembling of the hand tongue; similar to muscle weakness, If you are standing up from a sitting position or sitting up in a lying position, you need to support your hand.

7. Early symptoms of pregnancy-induced hypertension syndrome, such as edema, high blood pressure, and proteinuria.

8. Fetal growth restriction (FGR) The mother's weight gain is slow or does not increase, the uterus is high, the abdominal circumference is increased slowly and less than the gestational age, and the B-ultrasound is used to calculate the fetal weight less than the gestational age. 10 percentile.

Hyperthyroidism combined with pregnancy examination

1. Pregnant women suspected of hyperthyroidism, should promptly perform thyroid function test, the majority of patients with hyperthyroidism FT4, FT4I increased and TSH decreased, individual subclinical hyperthyroidism patients with FT4 in the normal range or the upper limit of the normal range, need to determine TSH, A reduction in TSH can also confirm the diagnosis.

2. Determination of TSHRAb (refer to TSI), has important reference significance for women with Graves disease, such as:

(1) Fetuses or newborns who have given birth to hyperthyroidism in the past pregnancy;

(2) active hyperthyroidism, being treated with ATD;

(3) There is hyperthyroidism that has been or is being relieved. At present, thyroid function is normal, but fetal tachycardia;

(4) fetal growth restriction;

(5) Ultrasound examination determines fetal goiter, if the increase in TSHRAb predicts fetal or neonatal hyperthyroidism.

3. Hyperthyroidism caused by various causes, in laboratory examination and clinical characteristics, such as patients with Graves disease, clinically prominent eyes, serological examination can be found TSI.

In patients with subacute thyroiditis, in addition to the common features of hyperthyroidism, there are fever, fatigue, sweating, chills and other symptoms, normal blood cell count is normal, erythrocyte sedimentation rate is significantly accelerated, this disease occurs mostly in spring and autumn, thyroiditis is often accompanied by Pharyngitis, mumps and respiratory tract infections, mild thyroid enlargement, local tenderness, subacute thyroiditis with temporary hyperthyroidism, and no need for anti-thyroid drugs.

4. Hyperthyroidism caused by chronic lymphatic thyroiditis, seen in the early stage of the disease, the thyroid function is reduced in the late stage of the disease, the thyroid texture is tough, and serum levels are found to increase anti-thyroid antibody levels, including globulin antibodies and peroxides. Enzyme antibody assay.

5. Trophoblastic disease has the primary disease characteristics, elevated blood HCG is an important marker, and hyperthyroidism is accompanied by symptoms.

6. Serum calcium and alkaline phosphatase are elevated, and about 10% to 27% of patients with hyperthyroidism have elevated serum calcium, which is caused by bone loss, and occasionally hyperthyroidism combined with hyperparathyroidism.

It is not advisable to perform 131I examination during gestation period. In the past, the basal metabolic rate (BMR) was applied, and the BMR of patients with hyperthyroidism was elevated, but the accuracy rate was only 50%.

Differential diagnosis of hyperthyroidism combined with pregnancy

The diagnosis of hyperthyroidism should include the assessment of thyroid function and the determination of the cause of hyperthyroidism. At the same time, the combination should be assessed. Because there are overlaps between the symptoms and signs of pregnancy and hyperthyroidism, attention should be paid to the diagnosis. The appetite does not increase in weight and the action of Valsalva does not relieve the mother. The tachycardia is helpful for the diagnosis of hyperthyroidism. If the patient has been diagnosed with hyperthyroidism and is still being treated, the medical history data can be clearly diagnosed. If the hyperthyroidism in pregnancy is recurring or hyperthyroidism is found in pregnancy, then Pregnant women with symptoms of hyperthyroidism can be diagnosed by examining FT3, FT4, and high-sensitivity TSH. If FT3, FT4 is elevated, TSH is lowered, and hyperthyroidism can be established. It is not appropriate to make subclinical hyperthyroidism when TSH is lowered. The characteristics of TSH itself during pregnancy, due to elevated thyroglobulin in the blood during pregnancy, TT3, TT4 increased accordingly, so TT3, TT4 is less meaningful for the diagnosis of hyperthyroidism during pregnancy, TT3, TT4 increased and TSH is slightly lower It is not advisable to make a diagnosis of hyperthyroidism easily. If TRAb and/or thyroid peroxidase antibody (TPOAb) is positive, it is diagnosed as autoimmune thyroid. The disease has certain suggestive significance. The method of introducing radionuclide into the body during pregnancy is strictly prohibited. In order to prevent the destruction of fetal thyroid tissue, the thyroid function is low. Because the fetus has iodine function since 12 weeks of pregnancy, there are two Situation:

1. Pregnancy with hyperthyroidism

Physiological changes during pregnancy, such as heart palpitations, hyperhidrosis, heat resistance, increased appetite and other high metabolic syndrome and even physiological goiter are very similar to hyperthyroidism; weight loss caused by hyperthyroidism is concealed by pregnancy weight gain; pregnant women's high female Hormone causes elevated TBG, and blood TT3 and TT4 increase accordingly; these all cause difficulties in the diagnosis of hyperthyroidism, such as weight does not increase with the number of months of pregnancy, or muscle loss in the proximal limbs, or heart rate at rest at 100 More than /min should be suspected and hyperthyroidism; such as blood FT3, FT4 increased, TSH <0.5mU / L can be diagnosed as hyperthyroidism, such as accompanied by J diffuse goiter, thyroid tremor or vascular murmur, blood TSAb positive exclusion other After the cause of hyperthyroidism, it can be diagnosed as GD.

2. hCG related hyperthyroidism

hCG is identical to the subunit of TSH, and the receptor molecules of the two are very similar. Therefore, the binding of hCG and TSH to the TSH receptor is cross-reacted, and when the secretion of hCG is significantly increased (such as choriocarcinoma, hydatidiform mole or invasive hydatidiform mole, In multiple pregnancy, etc., hyperthyroidism (also known as hyperemesis hyperthyroidism, HHG) may occur due to stimulation of TSH receptor by a large number of hCG (or hCG analogues). The patient's hyperthyroidism varies in severity, blood FT3, FT4 is elevated, TSH Decreased, TSAb and other thyroid autoantibodies were negative, but blood hCG was significantly elevated. hCG-related hyperthyroidism often decreased with changes in blood hCG, and disappeared after termination of pregnancy or delivery.

Different from hyperemesis of hyperemesis in pregnancy, 8 to 14 weeks of gestation, due to hCG stimulation of thyroid FT4, FT3 is elevated, TSH can be moderately inhibited, but TSH is not less than 0.1mU/L, TSAb is negative, suggesting hyperemesis Type hyperthyroidism.

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