Hyperthyroidism in pregnancy

Introduction to hyperthyroidism during pregnancy The thyroid gland undergoes a large physiological change during normal pregnancy. The thyroid activity is increased by the placenta producing hCG and chorionic thyrotropin (hCT). The increase of estrogen promotes the increase of liver thyroid-binding globulin (TBG) and slow degradation, making the pregnancy thyroid gland Increased, blood vessels rich, increased iodine intake, about 80% of pregnant women increased by 3 times compared with non-pregnant state. Clinically, there is a high metabolic state similar to hyperthyroidism, hyperthermia, increased appetite, and increased heart rate. Hyperthyroidism during pregnancy includes hyperthyroidism with pregnancy and hyperthyroidism during pregnancy. Hyperthyroidism during pregnancy is mostly Graves' disease, mainly caused by autoimmune processes and mental stimulation, characterized by diffuse goiter and exophthalmos. basic knowledge The proportion of illness: 0.001% Susceptible population: pregnant women Mode of infection: non-infectious Complications: pregnancy-induced hypertension syndrome, premature delivery, congestive heart failure

Causes of hyperthyroidism during pregnancy

Causes:

The cause of Graves' disease during pregnancy is unclear. It may be related to autoimmune disorders. It occurs mostly in genetically susceptible individuals. It has a family tendency and is prone to occur in individuals with HLA-B8 and -DW3 haplotype genes.

Prevention of hyperthyroidism during pregnancy

Pay attention to rest, work and rest, life in an orderly manner, and maintaining an optimistic, positive and upward attitude towards life can be of great help in preventing diseases.

Hyperthyroidism complications during pregnancy Complications, pregnancy-induced hypertension, premature congestive heart failure

Pregnancy hypertension

As the level of T4 increases, the amount of peripheral catecholamines increases, and the increase in vasopressor increases the incidence of pregnancy-induced hypertension syndrome.

2. Fetal injury

The clinical manifestations are fetal growth retardation, or stillbirth. According to statistics, the total abortion rate of hyperthyroidism during pregnancy is 7.9%. In pregnant women who have not been treated or hyperthyroidism, 25% have stillbirth, while the premature birth of pregnant women with hyperthyroidism is significantly lower than that of newborns. Patients with normal thyroid function, but if pregnant women with early pregnancy develop hyperthyroidism, treatment with ATD does not increase the incidence of congenital malformations.

3. Thyroid crisis

It is characterized by high fever above 39 °C, pulse >140 beats/min, atrial fibrillation or atrial flutter, irritability, sweating, nausea, anorexia, vomiting, diarrhea, massive loss of water, shock and even coma, sometimes palpitations, jaundice, blood Increased white blood cells and higher maternal mortality.

4. Other

Hyperthyroidism during pregnancy is not controlled, and pregnant women are also prone to congestive heart failure.

Symptoms of hyperthyroidism during pregnancy Common symptoms Genital tension, hyperthyroidism, weight loss, fatigue, anxiety, diarrhea, heart rate, increased goiter after childbirth

Normal pregnancy due to changes in maternal thyroid morphology and function, in many ways similar to the clinical manifestations of hyperthyroidism, such as tachycardia, increased cardiac output, increased thyroid, warm skin, hyperhidrosis, aversion to heat, hyperthyroidism, etc., in pregnancy And are common in hyperthyroidism.

Mild hyperthyroidism had no significant effect on pregnancy, but the rate of abortion, the incidence of pregnancy-induced hypertension, preterm birth rate, the incidence of full-term infants, and perinatal mortality increased in patients with moderate to severe hyperthyroidism and uncontrolled symptoms. The cause of the effect of hyperthyroidism on pregnancy is still unclear. It may be caused by excessive consumption of nutrients by hyperthyroidism and high incidence of pregnancy-induced hypertension, which may affect the function of placenta.

Due to the placental barrier during pregnancy, only a small amount of T3 and T4 can pass through the placenta, so it does not cause neonatal hyperthyroidism. Pregnancy has little effect on hyperthyroidism. On the contrary, pregnancy often causes the condition of hyperthyroidism to be relieved to varying degrees. However, pregnancy combined with severe hyperthyroidism, due to pregnancy can increase the burden on the heart, and increased the original heart disease in patients with hyperthyroidism. Individual patients may induce hyperthyroidism due to childbirth, postpartum bleeding, and infection.

Examination of hyperthyroidism during pregnancy

1. Serum total thyroxine (TT4I) 180.6 nmol / L (140 g / L).

2. Total triiodothyronine (TT3) 3.54 nmol/L (2.3 g/L).

3. Free thyroxine index (FT4) 12.8.

Diagnosis and diagnosis of hyperthyroidism during pregnancy

Diagnostic criteria

High metabolic syndrome, serum total thyroxine (TT4) 180.6nmol / L (14g / dl), total triiodothyronine (TT3) 3.54nmol / L (230ng / dl), free thyroxine index ( FT4I) 12.8. The condition of hyperthyroidism is the highest level of TT4 <1.4 times the upper limit of normal value for mild hyperthyroidism; >1.4 times the upper limit of normal is moderate hyperthyroidism; there are crisis, hyperthyroidism and heart failure, myopathy and other severe hyperthyroidism.

Differential diagnosis

1. Simple goiter during pregnancy

Especially pregnant women are neurotic, their mental and emotional performance is very similar to hyperthyroidism pregnant women, but the pulse <100 times / min, pulse pressure difference <50mmHg (6.7kPa), cold palm, no micro tremor, normal knee reflex, thyroid enlargement Not significant, no vascular tremors and murmurs can be heard, no eyes gaze and exophthalmos. Laboratory sera examination of various thyroid function indicators are within the normal range of pregnancy.

2. Subacute thyroiditis

(1) Hyperthyroidism: the most common thyroid disease during pregnancy in adolescent or elderly women. Patients often have clinical manifestations of hypermetabolism, such as palpitations, heat, sweating, nervousness, irritability, and hand shake. Serum TT4, TT3, FT4, FT3, etc. are elevated, so often misdiagnosed and given ATD treatment. However, patients often have a history of viral infection, rapid onset, chills and fever. The most characteristic is thyroid enlargement, pain, swelling and pain can start from one side, then expand to the other side, and then involve the whole thyroid gland, the diseased gland The body is hard and tender, and the pain is aggravated when chewing, swallowing, turning the neck or bowing. ESR is significantly accelerated (50 ~ 100mm / h).

(2) Remission period: When entering the remission period, the thyroid swelling and pain are alleviated, and the serum T4 and T3 concentrations are decreased.

3. Hashimoto disease: It is one of the main causes of thyroid enlargement. It is often diagnosed with unexplained heartbeat, shortness of breath, chest tightness and weakness of limbs. It is extremely difficult to distinguish the hyperthyroidism from this disease. These two autoimmune diseases can coexist at the same time, called Hashitoxicosis. Hashimoto's thyroiditis has a large goiter, strong and occasional tenderness. Laboratory serum tests during hyperthyroidism are difficult to identify. Cytological examination can be performed with small needle puncture, the results are accurate and reliable, and simple and safe.

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