Definition of hyperthyroidism
Hyperthyroidism (hyperthyroidism) is a common endocrine disorder caused by the overproduction of thyroid hormones. Women with hyperthyroidism often present with disrupted, reduced or amenorrhea menstruation and low fertility. However, there are many pregnancies in women with treated or untreated hyperthyroidism, with an incidence of about 1:1000-2500 pregnancies. The majority of hyperthyroidism in pregnancy is Graves’ disease, a condition caused primarily by autoimmune and psychiatric stimuli and characterized by diffuse goiter and proptosis.
Causes
The causes of hyperthyroidism during pregnancy are essentially the same as those of hyperthyroidism during non-pregnancy, with Graves’ disease being the most common. This is followed by toxic nodular goiter and autonomic hyperfunctioning adenoma of the thyroid gland. In addition, hyperthyroidism can be seen in dramatic pregnancy vomiting, gravida, malignant gravida and chorioepithelial carcinoma.
Pregnancy and childbirth are a necessary part of every married woman’s life. In view of the fact that some symptoms shown by lesbians during pregnancy are quite similar to those of hyperthyroidism, it makes the diagnosis of hyperthyroidism during pregnancy difficult. In normal pregnant women, due to the hypertrophy of the anterior pituitary gland, the thyroid gland may become enlarged, and due to the increase in the level of estrogen in the blood, the thyroid binding globulin (TBG) may rise, and the total serum T3 and T4 may also rise accordingly. Because of these changes, normal pregnancy can be mistaken for hyperthyroidism, and the diagnosis of true hyperthyroidism with pregnancy can be delayed. Therefore, the diagnostic criteria for pregnancy with hyperthyroidism should be appropriately increased compared to that of hyperthyroidism alone. The basic requirements are: if the weight does not increase with the number of months of pregnancy, the pulse rate at rest is above 100 times/minute, and the proximal muscles of the extremities are wasted, the diagnosis of hyperthyroidism is suspected. If there are also eye signs, diffuse goiter, vascular murmur and tremor in the thyroid area, toxic diffuse goiter (Graves’ disease) can be diagnosed after excluding other causes of hyperthyroidism or thyrotoxicosis.
What to pay attention to in combined hyperthyroidism in pregnancy
1, ensure enough rest, keep your spirit happy and relaxed, pay attention to a reasonable mix of nutrition, pay attention to food containing high calories, high protein and high vitamins. Because the fetus takes a lot of calcium from the mother during pregnancy, and hyperthyroidism can cause calcium deficiency in pregnant women, so you should eat more food containing calcium, phosphorus and vitamin D, such as milk, dairy products, vegetables containing little oxalic acid, beans, seafood, bone broth, animal liver, eggs, etc. Those who are nervous can take appropriate sedatives, such as Valium, Librium. In mild cases, if the pulse rate is lower than 80 times/minute when sleeping, you can not take thyroid medication.
2. Radioisotope diagnosis and treatment are contraindicated to prevent the impact on the fetus. If the dose is too high, it may cause abortion during early pregnancy and affect the development of fetal thyroid gland, brain and bone.
Among the antithyroid drugs, PTU can block the conversion of T4 to T3 and has relatively little ability to pass through the placenta. (PTU: daily dose of 100-200mg is appropriate)
4. Rash, fever, arthralgia, vomiting, diarrhea, itching, etc., occurring during medication administration are drug side effects. The drug can be stopped or from the doctor’s guidance.
5. During pregnancy or after delivery, if the patient’s original symptoms worsen, and there is restlessness, drowsiness, fainting edge, high fever (above 39 degrees), heart rate of 140 beats per minute or more, it is called “hyperthyroidism crisis”, which is dangerous and should be hospitalized immediately.
6. Pregnancy combined with hyperthyroidism will put both the pregnant woman and the fetus at risk. Therefore, in addition to the above-mentioned matters, we should go to the hospital for obstetric checkups on time to detect abnormalities in a timely manner. During the late pregnancy, special attention should be paid to avoid mental stimulation and infectious diseases, and to be admitted to the hospital before the expected delivery date to prepare for the thought and treatment and to prevent hyperthyroidism.
Precautions for patients’ dietary life
Because of the excessive secretion of T3 and T4, the metabolic rate of hyperthyroidism is particularly high, and the demand for some nutrients is relatively increased, so hyperthyroidism patients should eat more food with high calories, high protein and rich in vitamins, and make up for the lost water.
2. Avoid eating foods with high iodine content, especially seafood such as kelp, sea fish and other seafood.
3, do not smoke, do not drink strong tea, coffee, wine, etc., do not eat spicy food, especially chili, onion, ginger, garlic, etc..
4, usually pay attention to rest, do not over-activity, and actively cooperate with the doctor’s treatment.
5. People around hyperthyroidism patients should also be considerate to the patients and try to relieve their tension to avoid aggravation of the disease.
Pre-conception and pregnancy counseling
It is recommended that women diagnosed with hyperthyroidism be treated first and wait for a period of time before pregnancy after they are cured.
For pregnant women with stable hyperthyroidism who are pregnant and are not planning to have an abortion, it is recommended to use medications that are not teratogenic and have less risk of passing through the placenta, such as PTU. 131 iodine should not be used for diagnosis and treatment. If 131 iodine treatment is applied before pregnancy, pregnancy should be carried out only after six months of contraception.
Pregnant women who are currently in a hypothyroid condition and are undergoing thyroid hormone supplementation therapy, thyroid hormone has no effect on the baby, and the medication cannot be stopped after pregnancy, as stopping the medication may cause miscarriage.
Prenatal care
Pregnant women with hyperthyroidism are prone to fetal growth restriction (FGR) and low birth weight because of their hyper-metabolism and inability to provide adequate nutrition to the fetus. Check-ups: Pay attention to the growth of mother’s weight, uterine height and abdominal circumference, and perform fetal ultrasound every 1-2 months to estimate fetal weight. Usually strengthen nutrition, pay attention to rest, and take the left side position. If FGR is detected, hospitalization should be prompt.
Pregnant women with hyperthyroidism taking ATD may cause fetal hypothyroidism: fetal goiter, slow weight gain, slow fetal heart rate of 110-120 beats per minute, reduced fetal movement, low amniotic fluid. In congenitally hypothyroid fetuses, the prognosis may be poor. It is suggested that the diagnosis can be made by umbilical cord puncture, and cord blood can be taken to check the nail function.
Labor and delivery
Ultrasound is used to observe the size of the fetal thyroid gland and whether there is any enlargement of the thyroid gland that may cause the fetal head to hyperextend. If there is any abnormality, it may cause obstructed labor and cesarean section will be considered. The choice of delivery method, except for obstetric factors, is usually vaginal and most of the deliveries are smooth.
Postnatal observation of the newborn and mother
After birth, pay special attention to the signs and symptoms of hypo- or hyperthyroidism.
Hypothyroidism in newborns: large tongue, frog’s belly, florid skin, no increase in body temperature, poor response, low tone, little food, delayed defecation, no weight gain; some have immature lungs and pulmonary hyaline membrane disease.
Neonatal hyperthyroidism (rare): Occurs several days after delivery (5-10 days), manifesting as small head, enlarged thyroid gland, protruding or open, gleaming eyes, high skin temperature, and in severe hyperthyroidism, accompanied by hyperthermia, accelerated heart rate and respiration, and other hyperthyroid crisis manifestations. There are also symptoms of hyperthyroidism such as crying, high milk consumption, frequent stools and lack of weight gain.
Therefore, it is recommended to extend the hospital stay of the newborn baby for observation, and to ask the family to come to the hospital for examination and follow-up if there is any abnormality after discharge.
Breastfeeding after delivery
PTU is better than MMI, if the mother takes PTU 200mg, tid, the newborn will get PTU 99μg per day.