Author of the article - an obstetrician Grigorieva Xenia S.
hypothyroidism - a disease which is caused by reduced thyroid function and, consequently, a decrease in the content tireodnyh hormones in the blood.
The disease occurs in 1.5-2% of pregnant women. The rarity is because when untreated hypothyroidism there is a high risk of infertility. Pathology can not be detected for a long time, since it is characterized by the gradual development and continuous secrecy of symptoms that can be confused with fatigue, pregnancy or other diseases.
Types and causes of
Hypothyroidism is a primary (99%) and secondary (1%). The first arises from the decrease in production of thyroid hormones, which causes a reduction in its functionality. The cause of primary hypothyroidism are disturbances in the gland itself, and the secondary - the defeat of the pituitary gland or hypothalamus.
Primary hypothyroidism is divided into subclinical and overt. Subclinical called when TSH (thyroid stimulating hormone) is increased in blood, and T4 (thyroxine) are normal. When the manifest - TTG increased, and T4 is reduced.
Norms of hormones in the blood:
- thyroid-stimulating hormone (TSH): 0.4-4 mIU / ml; Pregnancy: 0.1-3.0 mIU / ml;
- free thyroxine (T4): 9,0-19,0 pmol / L; Pregnancy: 7,6-18,6 pmol / L;
- free triiodothyronine (T3): - 2,6-5,6 pmol / L; Pregnancy: 2,2-5,1 pmol / L.
Hypothyroidism is divided into congenital and acquired.
Causes of hypothyroidism:
- thyroid and congenital anomalies;
- disorders the treatment of which can lead to iodine deficiency (Graves goiter);
- thyroiditis (Autoimmune, post-natal) - thyroid gland inflammation;
- thyroidectomy (surgery to remove the thyroid);
- thyroid tumors;
- Usage iodine deficiency (with the products or pharmaceutical preparation);
- congenital hypothyroidism;
- thyroid irradiation or treatment with radioactive iodine.
symptoms of hypothyroidism
Hypothyroidism in the body slows down performance of some systems due to lack of thyroid hormones produced by the thyroid gland. Disease severity depends on the degree and duration of the disease. Symptoms may occur individually or in combination. These include:
- forgetfulness;
- decreased alertness;
- loss and brittle hair;
- harsh voice (nocturnal snoring can occur due to edema of the larynx and tongue);
- spasmodic contraction of the muscles;
- swelling of the skin;
- general weakness (even in the morning);
- joint pain;
- depression;
- reduction capability;
- weight gain;
- reducing the frequency of respiration and heart rate (one of the most serious symptoms, heart rate may be less than 60 beats / min);
- dry skin;
- Body temperature decrease (by a feeling of chilliness);
- numbness in hands (due to compression of the nerve endings in the wrist swelling of tissues);
- visual impairment, hearing loss, ringing in the ears (due to tissue edema affects the senses).
Specificity of hypothyroidism in pregnancy
In pregnant women with hypothyroidism is one feature. With the development of the symptoms of pregnancy may be reduced. This is due to increased activity of the thyroid gland of the fetus and the receipt of his hormones to the mother as compensation.
With a weak effect of thyroid hormones on the immune system, there is a tendency to frequent infections.
In order to further develop the symptoms, you should immediately consult a doctor, to hand over all the necessary tests and start treatment as early as possible.
Diagnostics
Initially, the doctor must be notified if there is a genetic predisposition, and whether operations were on the thyroid gland.
The most effective method for the diagnosis of hypothyroidism - determination of TSH levels in the blood. Increased levels of the hormone indicates a low thyroid function, ie hypothyroidism and reduced - to hyperthyroidism.
Additional laboratory tests:
- biochemical and clinical blood tests;
- determination of blood clotting in each trimester;
- definition of protein-bound iodine in the blood.
Instrumental investigations:
- Thyroid ultrasound. It is determined by its volume (normally not more than 18 ml) and sizes. When acquired hypothyroidism dimensions may be normal, and congenital - increased or decreased.
- ECG.
- Ultrasound of the heart.
Important! Since 1992, Russia conducted a mandatory screening of newborns for hypothyroidism. TSH levels in the blood is determined on the 5th day of life, children with little weight or low Apgar scores - 8-10 day. 20 mIU / l is considered normal. If the values above, it is necessary to do re-examination, since it can be associated with the presence of physiologic neonatal hypothyroidism. Also, the ultrasound scan of the thyroid gland. In congenital hypothyroidism replacement therapy during the first year of life.
differential diagnosis
Primary or secondary hypothyroidism to determine pregnancy. Intravenously 500 mg of TRH (thyroliberine - hypothalamic hormone), provided that the blood TSH increased slightly or remained normal, it indicates secondary hypothyroidism. Also prior to pregnancy is necessary to exclude anemia, edema, deafness, alopecia (hair loss, abnormal hair loss) and others.
Hypothyroidism is also necessary to differentiate coronary heart disease:
- hypothyroidism marked bradycardia (low heart rate), and for heart disease - tachycardia (increased heart rate);
- if the pressure on the swelling and no trace remains, it indicates hypothyroidism;
- there are differences in the ECG data.
Treatment of hypothyroidism in pregnancy
Treatment of hypothyroidism during pregnancy is engaged endocrinologist in collaboration with an obstetrician.
In the first trimester necessarily performed prenatal (antenatal) diagnosis of possible abnormalities in the fetus. If uncompensated hypothyroidism indicated termination of pregnancy for medical reasons. But if a woman wants to continue childbearing, it is a replacement therapy with levothyroxine sodium (L-thyroxine). Compensated hypothyroidism (when reception level normalization TTG) is not a contraindication in pregnancy, the same treatment is conducted.
Before pregnancy replacement therapy with L-thyroxine is 50-100 mg / day. After its onset, increase the dose to 50 mg, no risk of overdose is there, on the contrary, decreased levels of thyroid hormones in the blood of the fetus. Sometimes it happens that some pregnant women from 20 weeks after hormonal research there is a need to increase the dose. TTG replacement therapy should be below 1.5-2 mIU / L.
Levothyroxine sodium is available in tablets of 50 and 100 micrograms (e.g., Eutiroks). The drug is taken in the morning for half an hour before a meal, if you have morning sickness, it is better to take at a later time.
In hypothyroidism thyroid hormone can not be restored, so replacement therapy is necessary to maintain a constant, lifelong.
delivery
Many pregnant women with hypothyroidism in the background give birth to full compensation on time and without complications. Cesarean section is performed only for obstetric indications.
In hypothyroidism sometimes it happens such complication in delivery as weak labor. Delivery in this case may be either through natural ways and by caesarean section (depending on the display).
In the postpartum period there is a risk of bleeding, so need prophylaxis (administration of drugs which reduce the uterus).
Possible complications of hypothyroidism to the mother and fetus
There is the risk of congenital hypothyroidism in the fetus. If the disease is time to identify, it is easy to correct by using substitution therapy.
Possible complications:
- miscarriage (30-35%);
- preeclampsia;
- weak labor;
- bleeding in the postpartum period.
Possible complications uncompensated hypothyroidism:
- hypertension, preeclampsia (15-20%);
- placental abruption (3%);
- post-partum bleeding (4.6%);
- little fetal body weight (10-15%);
- fetal abnormalities (3%);
- intrauterine fetal death (3-5%).
Forecast
With timely and adequate treatment is minimal risk of complications. necessarily require replacement therapy during the whole period of pregnancy to the favorable course of pregnancy and fetal development. In congenital hypothyroidism in a pregnant woman needed medical and genetic counseling.
The statistics are taken from the site Federal Library of Medicine (Thesis: "Krivonogova M. E. Status of the fetus in pregnant women with iodine deficiency diseases ")
Some studies in pregnancy
- Smears during pregnancy.
- Tests during pregnancy by trimester.
- Ultrasound during pregnancy.
- Urinalysis in pregnancy.
- Coagulation.
- Installing pessary.
- Glucose tolerance test.
- Homocysteine in pregnancy.
- Amniocentesis.
- Anesthesia during childbirth.
- Fetal CTG (cardiotocography)
- Cordocentesis.
- Epidural anesthesia during childbirth.
