Hypothyroidism in pregnancy - what every young woman needs to know
Hypothyroidism is a syndrome caused by a persistent lack of thyroid hormones. The incidence of pathology among women carrying a child reaches 2%. Pregnancy with hypothyroidism requires careful medical observation, because the lack of correction of this condition is fraught with negative effects on the fetus.
The thyroid gland is a part of the endocrine system that has a direct or indirect effect on virtually all systems of the body. For this reason, it is important to know how hypothyroidism can be dangerous during pregnancy. To understand the mechanism of development of thyroid hormone deficiency, its causes should be considered.
Depending on the factor that caused the decrease in thyroid hormone levels, there are several types of hypothyroidism.
It is 95% of all forms of hypothyroidism. Caused by direct lesion of the thyroid gland. Most often we are talking about damage to the tissue of the organ or its functional failure.
This can lead to:
- Autoimmune thyroiditis. It is an inflammatory disease of the thyroid gland. Autoimmune hypothyroidism is often found during pregnancy.
- The consequences of surgical treatment. Hypothyroidism can develop after the removal of the entire thyroid gland, or part of it.
- Anomalies of development. We are talking about agenesis (congenital absence) and dysgenesis (malformation) of the thyroid gland.
- Infectious diseases. Often lead to inflammation complications of SARS.
- Treatment with radioactive iodine. Used in the fight against malignant neoplasms.
- Transient hypothyroidism. Sometimes develops due to postpartum thyroiditis.
Other primary hypothyroidism occurs during pregnancy more rarely and is caused by a disorder of the synthesis of thyroid hormones.
- The intake of thyroid-stimulating toxins, the use of certain medications.
- Congenital disorder of the thyroid gland synthetic function.
- Severe deficiency or excessive iodine content in the body (for this reason, iodomarin with established hypothyroidism during pregnancy is recommended to be taken only with the permission of the attending physician).
The syndrome is caused by damage to the pituitary gland. The anterior lobe of this endocrine gland, located in the brain, secretes a thyroid-stimulating hormone. TSH acts as a stimulator of the thyroid gland. Suppression of the pituitary gland provokes a decrease in the production of thyroid hormones. More about TSH during pregnancy →
Pathology is due to the disruption of another part of the endocrine system - the hypothalamus, also located in the brain. This nerve center has a stimulating effect on the secretion of pituitary TSH by secreting thyrotropin-releasing hormone. The overwhelming effect on the hypothalamus can lead to thyroid insufficiency.
Such hypothyroidism during pregnancy requires careful examination, as it may be one of the secondary signs of serious damage to the brain structures. The primary and secondary deficiency of thyroid hormones is called central hypothyroidism.
Extremely rare cases of this type of syndrome are usually recorded in the form of family forms. Pregnancy with the considered congenital hypothyroidism should be planned and carried out under close endocrinological observation. Peripheral hypothyroidism is due to the reduced sensitivity of the body's tissues to thyroid hormones. At the same time, there is a lack of gross violations in the work of the thyroid gland, hypothalamus and pituitary.
The clinical course of hypothyroidism directly depends on the duration and severity of thyroid hormone deficiency. Often the pathology proceeds covertly. So, subclinical hypothyroidism does not cause complaints during pregnancy and after childbirth.
Hormonal disorders of moderate and severe manifestation in the form of "masks" of various diseases. For example, one can speak about the consequences of uncompensated hypothyroidism in the event of an arrhythmia that is not actually associated with a primary lesion of the heart.
Syndromes of hypothyroidism:
- Hypothermic exchange. Includes obesity and a decrease in body temperature. The first symptom, which accompanies gestational hypothyroidism (lack of thyroid hormones during pregnancy), is often perceived as a physiological increase in body mass during gestation. Violation of fat metabolism leads to increased cholesterol levels.
- Nervous System Syndrome. Hypothyroidism in pregnancy is often accompanied by symptoms that can be confused with signs of gestational encephalopathy, a condition caused by the reversible hormonal alteration of the female body. Future mom may be worried about memory loss, drowsiness, some lethargy, sometimes alternating with panic attacks.
- Anemic syndrome. There are signs of iron deficiency and vitamin B deficiency. Sometimes the diagnosis of "hypothyroidism" is missed because the symptoms in women resemble anemia during normal pregnancy.
- Syndrome of defeat of the cardiovascular system. In the early stages it manifests itself in the form of bradycardia (decrease in heart rate below 60 beats per minute). Typical hypothyroidism is accompanied by arterial hypotension. With severe hormonal disorders, signs of heart failure appear.
- Syndrome of defeat of the alimentary system. The patient's appetite decreases, there are signs of an enlarged liver. Constipation, caused by hypothyroidism, during pregnancy is attributed to compression of the growing uterus of the intestine.
- Syndrome of ectodermal disorders with hypothyroid dermopathy. There is swelling of the face, limbs, eye area. Hair becomes brittle, fall out (until the formation of areas of baldness).
- Obstructive hypoxemia syndrome. Manifested in the form of apnea (short-term stop breathing) in a dream.
Subclinical hypothyroidism during pregnancy
It is the most insidious form of hormonal disorders. Subclinical hypothyroidism does not bother a woman during pregnancy, so its effects can be serious due to late diagnosis. The aggravation of hormonal disorders will eventually lead to the appearance of clinical symptoms, but it is nonspecific.
Detect subclinical hypothyroidism during pregnancy by using laboratory tests. The main symptom is an increase in TSH against the background of normal levels of total T4 (tetraiodothyroxin). This is due to compensatory stimulation of the thyroid gland of the hypothalamic-pituitary system.
Subclinical hypothyroidism is not a reason for panic during pregnancy: the consequences for a child born on his background are usually not life-threatening. In 55% of cases, a relatively healthy newborn is born. Problems may be delayed, for example, in the form of reduced immunity.
Inflammatory damage to the thyroid gland is often found among women who bear the fruit. The risk group includes those in the early postpartum period. The relatively high frequency is explained by the carrier of antibodies to the thyroid gland's own tissues among 10-20% of pregnant women.
Autoimmune thyroiditis, triggered by autoantibodies, causes hypothyroidism that can disrupt pregnancy and, if not properly treated, adversely affect the unborn child. The disease occurs in hypertrophic and atrophic form. In the first case, we are talking about a compensatory increase in the size of the thyroid gland, in the second - about the replacement of the affected areas with connective tissue.
Pregnancy planning for hypothyroidism
The presence of hypothyroidism should not be overlooked when planning a pregnancy. Severe thyroid hormone deficiency can cause infertility. Treatment of previously established hypothyroidism should be carried out in advance: pregnancy, even if it has occurred, runs the risk of ending with spontaneous abortion or severe abnormalities in the development of the fetus.
Women who have not previously suffered from hypothyroidism are also advised to check the state of the thyroid gland during pregnancy planning. This is due to the ability to conceive a child with a subclinical form of pathology. If you do not determine the hormonal imbalance before pregnancy, then the signs of hypothyroidism that appeared later may go unnoticed during pregnancy.
Implications for a pregnant woman and child
A deficiency of thyroid hormones can have a negative effect on both the expectant mother and the fetus. Pathology is a particular danger in the first trimester, when the laying of organs and systems of the embryo occurs.
Uncompensated hypothyroidism during pregnancy can cause seriousconsequences for the child:
- Low birth weight.
- Lag in physical and mental development.
- Anomalies of the structure.
- Congenital hypothyroidism.
Severe hypothyroidism has a negative effect on pregnancy and can be dangerous for a woman. The aggravation of the pathology is explained by the use of maternal thyroid hormones by the fetus in the first half of pregnancy.
- Spontaneous abortion.
- Premature detachment of the placenta with severe bleeding.
- Weak generic activity.
- Iron-deficiency anemia.
Which doctor should I refer to for hypothyroidism during pregnancy?
Maintaining the entire period of pregnancy with hypothyroidism is carried out under the joint supervision of an endocrinologist and an obstetrician-gynecologist. The first specialist corrects the hormonal imbalance and monitors the results, and the second carries out prenatal diagnosis of possible abnormalities in the fetus and monitors the course of gestation. This allows minimizing possible risks awaiting the future mother and her child.
Hypothyroidism, correctly compensated during pregnancy, does not entail dangerous consequences for the child and mother. The basis of treatment is hormone replacement therapy. The medications are drugs containing levothyroxine sodium: Eutirox, L-thyroxin, Bagothyrox.
The dosage is determined by the endocrinologist and ranges from 50 to 150 mg per day. The drug is taken in the morning for half an hour before meals. Levothyroxine sodium does not restore the function of the thyroid gland, but only replaces its work.
There are no popular recipes for obtaining levothyroxine sodium at home. Pregnancy occurring with hypothyroidism of the thyroid gland requires special care and does not tolerate self-treatment. Reception of any preparation should be coordinated with the doctor.
Most of the popular recipes are focused on taking products containing iodine. However, its excessive intake may aggravate hypothyroidism and adversely affect pregnancy. To safe ways to compensate for iodine deficiency is moderate consumption of dishes from sea kale.
Examples of recipes published in online sources that should NOT be resorted to:
- Iodine solution with apple cider vinegar inside. This method will not only cure hypothyroidism during pregnancy, but also cause life-threatening consequences: first, you can get a burn, and second, poisoning with a high dose of iodine.
- Juniper and butter ointment. Any external influence on the thyroid gland is undesirable. This is especially the case when nodes are found in the organ.
Is there a prevention?
Specific methods of prevention are not developed. The main measures are aimed at timely correction of existing violations.
In order to prevent hypothyroidism during pregnancy and to avoid its possible complications, you should follow the recommendations:
- Control thyroid hormone levels when planning a pregnancy.
- Acceptance of iodine-containing drugs as prescribed by the attending physician.
- Consideration of the features of therapeutic regimens when using levothyroxine.
- Prevention of infectious diseases, exclusion of contact with toxic substances.
It is important to remember how much hypothyroidism affects pregnancy. The underestimation of the significance of the “small” endocrine gland can lead to dangerous consequences for both the child and the mother. The key to a normal pregnancy is a timely appeal to the endocrinologist and gynecologist, as well as the implementation of their recommendations.
Author: Kristina Mishchenko, doctor,
specifically for Mama66.ru
According to severity, there are 3 forms of hypothyroidism:
- SUBCLINICAL. It is characterized by the absence of signs and symptoms of the disease. In the blood there may be a normal content of thyroid hormones, but always an elevated level of TSH. Subclinical hypothyroidism affects no more than 20% of women.
- CLASSIC OR MANIFEST. Always accompanied by deterioration in health. Blood levels of hormones are lowered, but TSH is elevated.
- HEAVY. It is characterized by a long course of the disease in the absence of adequate treatment. Typically, the outcome - coma.
Hypothyroidism during pregnancy is the cause of reduced metabolism. Since the thyroid hormone receptors are located almost throughout the body, there is a disruption in the work of many organs and systems. The severity depends on the level of hormonal deficiency. It is for this reason that it is difficult to suspect the disease at an early stage, and in fact it is very important for the fetus to receive the necessary amount of thyroid hormones in the first 12 weeks of pregnancy, during the formation of internal organs.
Maintaining a pregnant woman with hypothyroidism
If a pregnant woman has a thyroid disease, she is assigned a separate plan for managing the pregnancy:
- The question of the preservation of pregnancy.
- A woman is observed by an obstetrician together with an endocrinologist.
- Genetic counseling is prescribed, often amniotic fluid is taken for analysis to exclude congenital malformations in the fetus.
- Even mild and asymptomatic hypothyroidism is treated.
- All women in the first trimester of pregnancy are recommended to take iodine preparations.
- During pregnancy, hormone levels are examined several times.
- Women go to the maternity hospital in advance to decide on the method of delivery, which are more often premature. After birth, the child must undergo medical genetic counseling.
What could be the consequences for the child?
Thyroid hormones have the most important influence on the formation and maturation of the brain of a newborn. No other hormones have a similar effect.
The negative effects of hypothyroidism during pregnancy on the fetus:
- high risk of spontaneous abortion,
- congenital malformations of the heart,
- hearing loss
- congenital malformations of the internal organs.
- congenital hypothyroidism, which develops in children born to mothers with untreated hypothyroidism. This is the worst consequence for the fetus, is the main cause of the development of cretinism. Cretinism is a disease caused by thyroid hypofunction. Manifested by delayed mental and physical development, late teething, poor closing of fontanelles, the face takes on characteristic thick and swollen features, body parts are not proportional, the child’s genital system suffers
After the diagnosis is established, the child is prescribed a lifelong dose of drugs that replace thyroid hormones as early as possible. The sooner the child begins treatment, the greater the chances for the normal development of his mental abilities. Next, every quarter of the year, the treatment is monitored — the child measures height, weight, overall development, and hormone levels.
TRANSITORAL HYPOTHYRIOSIS. Temporary disease of newborns, which passes independently and without a trace. It is more common in regions with iodine deficiency, in premature babies, if the mother took drugs that inhibit the hormonal activity of the thyroid gland. In this case, the child is prescribed treatment as in hypothyroidism, if after repeated analysis the diagnosis is not confirmed, all drugs are canceled.
Hypothyroidism during pregnancy
According to research in the field of obstetrics and gynecology, the prevalence of hypothyroidism in pregnant women reaches 1.8-2.5%, while in the population as a whole this indicator is 0.5-2.0%. In more than 40% of these patients, antibodies to thyroid enzymes are detected, and in 15% sonography of the organ is confirmed sonographically. A separate risk group consists of 10-15% of patients with clinically significant content of antibodies to TPO (thyroperoxidase) and normal levels of thyroid hormones. By the time of birth, in 20% of them the level of thyroid-stimulating hormone rises to the indicators characteristic of subclinical hypothyroidism. The relevance of timely diagnosis of thyroid hypofunction is due to the high risk of miscarriage and the development of other obstetric complications.
Causes of hypothyroidism during pregnancy
The thyroid hormone deficiency that arose prior to the onset of gestation is most often caused by autoimmune thyroiditis (Hashimoto disease), a disease with a hereditary predisposition, in which autoantibodies are formed to the tissues of the thyroid gland. In this pathology, the phase of hyperthyroidism, characteristic of the initial stages of the inflammatory-destructive process, is soon replaced by hormonal insufficiency. Other causes of hypothyroidism in women of reproductive age are hypothalamic-pituitary dysfunction, hypoplasia or aplasia of the thyroid gland, its resection in tumors, diffuse toxic goiter, destruction of thyroid tissue in trauma, radioiodine therapy. Hormone deficiency can be associated with an overdose of thyreostatic drugs, iodine deficiency in food and water, and frequent pregnancies with a long lactation period. During the period of gestation, a number of specific factors promote the development of hypothyroid states:
- Immune restructuring after childbirth. The physiological suppression of immunity in a pregnant woman is aimed at reducing the risk of fetal rejection and interruption of gestation. Against the background of postpartum immune reactivation, transient autoimmune aggression is possible. At the same time, in predisposed women with thyroid peroxidase autoantibodies (AT-TPO), the probability of postpartum thyroiditis reaches 30-50%, and in patients with insulin-dependent diabetes mellitus and other autoimmune disorders, the prevalence of pathology is 3 times higher than in the general population.
- Iodine deficiency associated with gestation. The need of a pregnant woman for iodine increases significantly, due to the use of this trace element to ensure the normal functioning of the placental complex and the exchange-plastic processes in the body of the fetus. The situation is exacerbated by increased renal iodine clearance during pregnancy. An additional factor causing relative hypothyroxinemia in the absence of iodine prophylaxis is the activation of type 3 deiodinase, under the action of which thyroxin (T4) is transformed into biologically inactive reversible triiodothyronine (rT3).
- Functional overload of the thyroid gland. In the first trimester, under the influence of estrogens and human chorionic gonadotropin, physiological hyperthyroidism develops, aimed at meeting the needs of the fetus in thyroid hormones. With insufficient functional reserve, the organ overload experienced during gestation can serve as a trigger for the formation of simple non-toxic goiter, the transition of asymptomatic autoimmune thyroiditis to manifest stage, the occurrence of other thyroid disorders in susceptible patients.
Sometimes hypothyroidism, formed after pregnancy, becomes a manifestation of Shihan syndrome - necrosis of the pituitary tissue due to massive blood loss, infectious-toxic shock, DIC after complicated abortion or difficult childbirth. In such cases, a lack of thyroid hormones develops on the background of multiple endocrine insufficiency.
The mechanism of hypothyroidism during pregnancy is determined by the reasons that caused the disorder. An important link in the pathogenesis is a hereditary predisposition, which is manifested by a tendency to autoimmune reactions and a low functional reserve of thyroid tissue. Physiological hyperstimulation of the thyroid gland, enhanced excretion of iodine with urine and its transplacental transfer lead to a relative iodine deficiency, which contributes to the manifestation of subclinical hypothyroidism. In the postpartum period, the depletion of the thyrocyte cell reserve as a result of their destruction by auto-aggressive antibodies plays an additional role.
With a low content of thyroxine and triiodothyronine, the metabolism slows down significantly, the body temperature decreases. The organs and tissues accumulate glycosaminoglycans - highly hydrophilic protein metabolites that can trap fluid in the skin, mucous membranes, and internal organs. As a result, common mucoid edema develops. In the long-term period, a woman with hypothyroidism, manifested after childbirth, suffers from positive ovarian-pituitary feedback, the menstrual cycle is disturbed, anovulation, hypomenorrhea, and amenorrhea occur.
Symptoms of hypothyroidism during pregnancy
When subclinical course of the disease is not defined. In the decompensated state, there are complaints of lethargy, low performance, rapid fatigue, drowsiness, chilliness, loss of appetite, nausea, and constipation. A pregnant woman becomes forgetful, inattentive, apathetic, quickly gaining weight. Hypothermia, rare pulse, paleness, dryness and peeling of the skin, hair loss and nails, brittle nails, myxedematous edema of the extremities, hoarseness, snoring during sleep are characteristic. Possible headache, muscle, joint pain, numbness of the hands. Sight and hearing often deteriorate, ringing in the ears appears.
Due to fertility disorders in patients suffering from clinically pronounced hypothyroidism, pregnancy occurs rarely, often has a complicated course and in 35-50% of cases ends with spontaneous abortion or premature birth. Every third pregnant woman has an early toxicosis. Up to 3.3% of the fruits have developmental abnormalities, including those caused by structural and quantitative chromosomal aberrations. Gestational hypertension and preeclampsia are observed in 15-22% of patients, fetal hypotrophy - in 8.7-16.6%, and antenatal death of a child - in 1.7-6.6%. In 70% of cases, placental insufficiency develops. Possible prolonged pregnancy, weakness of labor, premature detachment of a normally located placenta. In 3.5-6.6% of puerperas, coagulopathic postpartum bleeding occurs. The hypogalactia is characteristic.
In children born to women with untreated hypothyroxinemia, low IQ and other intellectual disorders are more common. According to the observations of specialists in the field of endocrinology, childbearing also affects the development of the disorder that caused hypothyroidism - during pregnancy, the likelihood of the clinical manifestation of asymptomatic (euthyroid) autoimmune thyroiditis increases, and women with circulatory AT-TPO are associated with depression. Severe complication of hypothyroidism during gestation is myxedema coma.
Subclinical hypothyroidism due to the asymptomatic course is extremely rare. The basis for the appointment of laboratory tests, allowing to verify the violation, are the anamnestic information about the autoimmune diseases of the patient, her parents, siblings. In the presence of complaints and data of physical studies indicating a possible dysfunction of the thyroid gland, the patient is recommended:
- TTG level determination. The assay is marker for primary hypothyroidism. In the subclinical variant of the disorder, the concentration of thyroid-stimulating hormone is increased to 4-10 mIU / l, with a manifest indicator of more than 10.0 mIU / l and more.
- Analysis of thyroid hormones. In pregnant women with subclinical hypothyroidism, normal rates of T4, T3 are determined. After the manifestation, the concentration of free triiodothyronine does not exceed 4 pmol / l, free thyroxine - 10 pmol / l.
- Detection of antibodies to thyroperoxidase. Since most cases of hypothyroidism are associated with an autoimmune thyroid disease, the study reveals auto-aggression. Diagnostic significant indicator is from 34 IU / ml.
To determine the volume of thyroid tissue, the detection of possible structural changes is carried out ultrasound of the thyroid gland. An organ puncture biopsy is performed in doubtful cases if neoplasia is suspected. As additional methods, ECG and ultrasound of the heart are shown. Characteristic changes are detected in the general blood test: in 60-70% of patients there is lymphocytosis, an increase in ESR. In pregnant women suffering from hypothyroidism, anemia is usually more pronounced, cholesterol levels are elevated, and signs of hypercoagulation are noted.
Differential diagnosis is carried out between various diseases in which the production of thyroid hormones is reduced. When making a diagnosis, it is necessary to exclude ischemic heart disease, chronic nephritis, nephrotic syndrome, thyroid cancer. In addition to the obstetrician-gynecologist and endocrinologist, the patient is advised by a cardiologist, urologist, neuropathologist, neurosurgeon, dermatologist, oncologist.
Treatment of hypothyroidism during pregnancy
The main tasks of managing a patient with hypothyroxinemia are the complete medical compensation of the disorder, the correction of possible concomitant disorders, the elimination of prerequisites that can aggravate the pathological condition. Prolongation of pregnancy in the manifest form of hypothyroidism is allowed only with the appointment of hormone replacement therapy. The standard treatment regimen includes drugs such as:
- Thyroid Hormones. The dose of the synthetic levorotatory isomer T4 is selected gradually with the control of the content of thyrotropin and thyroxin in the blood serum once every 14 days. The correct selection of the dosage is indicated by the normalization of the concentration of thyroid-stimulating hormone at the level of 1.5-2 mMe / l. Hormone therapy is indicated for pregnant women not only with apparent hypothyroidism, but also with a subclinical form of the disorder.
- Iodine-containing drugs. Iodotherapy, carried out in violation of the secretion of T3, T4 on the background of iodine deficiency, can reduce the dose of hormonal drugs, and sometimes completely abandon their use. In order to avoid overdose, when developing a regimen for taking medications with iodine, the severity of clinical symptoms and the preservation of thyroid tissue during destructive processes are taken into account.
In the presence of organ disorders caused by hypothyroxinemia, symptomatic treatment with cardioprotectors, tissue metabolism stimulants, antiarrhythmic agents, nootropics, vitamin-mineral complexes, and immunostimulants is used. Natural labor is recommended for patients with compensated hypothyroidism. Caesarean section is performed according to obstetric indications.
The work of the thyroid gland on the background of gestation
Usually, pregnancy aggravates the course of an already existing subacute hypothyroidism in a woman. For a long time, the thyroid gland can work relatively stably, although the level of hormones produced by it is reduced. But they are enough to maintain the exchange processes at the minimum acceptable level of the norm. Against the background of pregnancy, hormone costs increase, but the thyroid gland cannot increase hormone production, which leads to increased manifestations of hypothyroidism.
In fairness, it is worth noting that pronounced hypothyroidism usually leads to infertility, since the thyroid gland also controls the reproductive function of women. Therefore, pregnancy can occur with such a diagnosis only after therapy and the normalization of hormonal levels.
What do buyers say?
We looked at the reviews of the parent forum. All women leave positive feedback, arguing that their health after taking the drug improved, they felt a surge of strength and energy. We found reviews where parents said that after taking the drug, according to the ultrasound results, changes in the fetus were revealed in a positive way. There are no negative reviews on the parents forum.
We urge all women during pregnancy and lactation to prevent iodine deficiency with Yodomarin, women with hypothyroidism to start treatment immediately.
Prognosis and prevention
Hormonal correction of hypothyroidism allows you to minimize the likelihood of complications for the mother and fetus. Women with thyroid diseases are advised to plan a pregnancy taking into account the opinion of an endocrinologist, after conception to register with the antenatal clinic before the 12-week period, to regularly visit an obstetrician-gynecologist. To reduce the risk of hypothyroidism during pregnancy, according to the indications, iodoprophylaxis is carried out, the ration is supplemented with products saturated with iodine (sea fish, algae, iodized salt). It is necessary to exclude significant physical and psycho-emotional stress.
During pregnancy, autoimmune damage to the thyroid gland is most often the cause of hypothyroidism. In this condition, the cells of the organ are destroyed, which disrupts the synthesis of hormones and leads to their deficiency. Other causes of pathology in pregnant women are quite rare.
In anticipation of a baby, hypothyroidism may develop against the background of a pronounced lack of iodine. This problem is particularly relevant for residents of some regions with a natural shortage of this element in the soil. It is primarily about the highlands and plains, remote from the sea coast. The majority of the Urals and Siberia, some areas in the central part of the country, as well as Moscow and the Moscow region are among the iodine deficient regions in Russia.
Pregnancy is a time when there is an increased need for thyroid hormones. In the first half of pregnancy, there is an increased production of hCG (human chorionic gonadotropin), which leads to a physiological decrease in the level of TSH and an increase in the synthesis of thyroid hormones. After 20 weeks, the concentration of thyroid hormones is reduced and maintained at a fairly low level until delivery.
Iodine deficiency is another serious problem that awaits a woman during pregnancy. While waiting for the baby, the need for this compound increases significantly. On the one hand, more iodine is required for adequate development of the fetus. On the other hand, during pregnancy, excretion of this element with urine is enhanced. Iodine deficiency can lead to the development of hypothyroidism, abortion and other serious complications.
Hypothyroidism and Conception
Hypothyroidism is one of the common causes of infertility in young women. A significant lack of thyroid hormones inhibits the functioning of the ovaries. There is a delay in the maturation of follicles, disrupted ovulation and the formation of the yellow body. Conception of a child under such conditions becomes impossible. Problems at this stage can also be associated with concomitant hyperprolactinemia (excessive production of the hormone prolactin in the pituitary gland).
Even if the conception of a child is successful, the probability of a favorable development of pregnancy against the background of pronounced hypothyroidism is extremely low. The first 8 weeks of embryo development occurs under the influence of the maternal hormones of the thyroid gland. With a significant shortage of these hormones, conceiving and carrying a child is not possible.
The thyroid gland is an organ that affects the work of the entire female body. Thyroid hormone receptors are found in almost all tissues, which explains the diversity of clinical signs of hypothyroidism. The severity of symptoms will depend on the level of hormones in the blood, as well as on the duration of the disease.
Typical symptoms of hypothyroidism:
- weakness and lethargy
- reduced performance
- fast fatiguability,
- slowness, lethargy,
- loss of attention and memory
- hearing loss, tinnitus,
- pains in muscles and joints,
- dry skin
- brittle nails and hair,
- prolonged constipation.
Many of the symptoms of hypothyroidism are due to tissue swelling and compression of nerve fibers. This is how protracted headaches, soreness in muscles and joints, numbness of limbs appear. Due to swelling of the vocal cords, the voice changes, it becomes low and hoarse. Many women begin to snore in their sleep as a result of swelling of the larynx. Against the background of hypothyroidism, hearing often deteriorates, various visual disorders appear. Characterized by hair loss, increased fragility of the nails and severe dryness of the skin.
A deficiency of thyroid hormones slows down the course of metabolic processes. Constant chilliness appears, body temperature decreases. The functioning of the immune system is impaired, which leads to frequent infections. Recovery from hypothyroidism is delayed, which is also due to the peculiarity of the immune system.
One of the most dangerous manifestations of hypothyroidism is a violation of the heart. Many women develop bradycardia (a slower heart rate of less than 60 beats per minute). Typical vascular lesion, increased blood cholesterol levels. During pregnancy, this condition can lead to the development of preeclampsia and other serious complications.
The course of hypothyroidism during pregnancy
Many women after the conception of the child there is a significant improvement. This phenomenon is associated with the physiological growth of thyroid hormones in early pregnancy. In the second half of gestation, for most women, all symptoms of hypothyroidism subside. A similar condition persists until birth.
Важный момент: если женщина принимала какие-либо гормональные препараты до зачатия ребенка, ей следует обязательно сказать об этом врачу. Избыток собственных гормонов щитовидной железы на ранних сроках беременности плюс прием препаратов может привести к возникновению тахикардии, перебоям в работе сердца и другим неприятным проявлениям. With the onset of pregnancy, it is imperative to consult a doctor and review the treatment regimen.
Consequences for the fetus
Deficiency of maternal thyroid hormones disrupts the development of the nervous system of the fetus (in particular, interferes with the normal myelination of nerve fibers). Lack of hormones affects the very early stages of pregnancy, which leads to irreversible consequences for the newborn. After the baby is born, there are significant mental disorders and mental retardation. Drug therapy such a condition is almost impossible.
With congenital hypothyroidism, the expectant mother should consult a geneticist. A direct relationship between the congenital pathology of the thyroid gland and the appearance of chromosomal abnormalities is noted. There is a possibility of congenital hypothyroidism in the fetus.
Uncompensated hypothyroidism is an indication for termination of pregnancy in the first trimester. If a woman wants to preserve a pregnancy, hormone treatment is provided.
The goal of therapy for hypothyroidism is to improve the condition of the pregnant woman, to remove the symptoms of the pathology and to reduce the risk of adverse outcome. With proper treatment, the likelihood of complications is quite low. Acceptance of hormonal drugs allows a woman to bear and give birth to a healthy child.
For the treatment of hypothyroidism used hormonal drug - levothyroxine sodium. The dosage of the drug is selected individually, taking into account the severity of the woman’s condition and individual tolerance. The treatment is carried out under the constant control of thyroid hormone levels. The concentration of TSH and T4 is determined every 14 days. With a properly selected treatment, the TSH level should be below 2 mIU / ml.
Births with compensated hypothyroidism occur in time. Perhaps the development of weakness of labor. In the postpartum period, the risk of bleeding increases.
Pregnancy with hypothyroidism should be planned. Before conceiving a child, you must be examined by an endocrinologist and a gynecologist. Competent therapy during pregnancy will avoid the development of complications and increase the chances of having a healthy baby.
Causes of hypothyroidism during gestation
If we talk about the causes that influence the development of hypothyroidism, including cases of a process that escalates during gestation, an autoimmune process that previously existed or started during gestation can lead to a similar situation. This is a damage to the thyroid tissue by antibodies that the immune system produces against the organ's own cells.
Hypothyroidism often becomes a consequence of an operation performed on the thyroid gland due to its various lesions (nodes, cysts, hyperthyroidism), administration of radiotherapy, treatment with thyrostatic drugs. Secondary hypothyroidism, if the thyroid gland itself is healthy, may be in the pathology of the pituitary gland. Also contributes to reducing the synthesis of hormones chronic lack of trace element iodine in food.
Pregnancy: How will hypothyroidism manifest?
Severe, long-term manifestations of hypothyroidism with severe lack of thyroid hormones usually lead to infertility. This is due to the fact that in such a situation, ovarian function is suppressed, ovulation does not occur and the formation of the yellow body supports the viability of the egg cell and the embryo. Pregnancy is possible against the background of the subclinical course of hypothyroidism, with a deficiency of hormones not expressed before its onset. But pregnancy requires the revitalization of the body, enhancing the synthesis of hormones, if they are not enough. With a decrease in the amount of hormones, such pathologies of pregnancy as early miscarriages or stillbirth may develop, and thyroid gland developmental defects are likely.
In addition, a malfunction of the gland provokes severe damage to the neural tube in the fetus, a pronounced intrauterine growth retardation, and multiple deformities are likely.
On the part of the health of pregnant women themselves, there may be such manifestations as decreased performance and lethargy, constant drowsiness with slowness and inhibition. Suffering from memory, attention may be dissipated, hearing impairment is likely. The expressed pathological gains of body weight, change of appetite and the persistent constipations which are not corrected by habitual methods are typical. There is dryness and peeling of the skin, brittle nails and hair loss in the head and on the body. With such a pregnancy, a decrease in body temperature, constant chilliness, development of pain in the joints, muscle aches with numbness in the hands, a decrease in the tone of the voice, an increase in the size of the tongue, and the appearance of snoring are likely. A decrease in contractions of the heart, low pressure, especially systolic, is revealed. Frequent infections as a result of reduced immunity.
Childbirth in hypothyroidism: what is the condition?
Births with compensated hypothyroidism are usually carried out naturally, but preliminary preparation is necessary. Indications for childbirth by caesarean section usually occur in the presence of serious obstetric complications. By themselves, the delivery of hypothyroidism does not complicate if the level of hormones is stabilized. Often after childbirth there may be complications with bleeding and hypotonia of the uterus. Children born to mothers with this pathology have a high risk of congenital hypothyroidism.
● Blood from a vein on TSH, free T4 and T3 (held monthly).
● Biochemical and clinical blood tests.
● Determination of blood coagulation (held every trimester).
● Determination of protein-bound iodine in the blood.
● Ultrasound of the thyroid gland (for women, its volume should not exceed 18 ml). The study is conducted every 8 weeks.
With the presence of overt hypothyroidism in a pregnant woman, the content of free T4 in the blood does not exceed 10 pmol / l, free T3 is 4 pmol / l, and the concentration of TSH is increased by more than 10 mIU / L. In subclinical hypothyroidism, the content of thyroid hormones may be within the lower limits of the norm, but the concentration of TSH in the blood will always be increased from 4 mIU / l to 10 mIU / l.
Types of hypothyroidism
According to severity and symptomatology, hypothyroidism has a classification:
- Primarycaused by organic or functional changes in the thyroid gland - the most common form.
- Secondarycaused by organic or functional changes in the pituitary gland - the rarest form.
- Tertiarycaused by organic or functional disorders of the hypothalamus.
Similarly, hypothyroidism differs according to analyzes of subclinical, manifest and complicated. With subclinical there is an increased level of TSH with other normal indicators, and with a manifest level an increased level of TSH and a reduced level of free T4. With subclinical (in other words, compensated) hypothyroidism, there are still no symptoms, but there are already changes in laboratory tests. This is a kind of primary stage of the disease without obvious manifestations. With manifest - there is a clinic and laboratory changes. Quite often it happens when subclinical hypothyroidism during pregnancy after childbirth turns into a manifest. Complicated hypothyroidism is characterized by a whole complex of associated diseases, such as heart failure, cretinism, secondary pituitary adenoma, and many others.
Causes of hypothyroidism in pregnant women
A hormone deficiency can occur:
• With a lack of iodine in the body or its excess.
• When treated with radioactive iodine 131.
• When exposed to ionizing radiation.
• When reducing tissue that secretes hormones.
• With autoimmune thyroiditis.
• After removing most of the thyroid tissue.
• In the absence of thyroid receptor in the thyroid gland (TSH - thyroid stimulating hormone).
• When a brain tumor that violates the secretion of TSH.
• After severe injuries and blood loss, in which the pituitary gland dies and hormone deficiency occurs.
In early pregnancy, the need for thyroid hormones increases, and as a result, the relative iodine deficiency develops. This leads to an increase in severity.
existing hypothyroidism, and may also cause decompensation of subclinical hypothyroidism.
Features of pregnancy with hypothyroidism
In hypothyroidism, ovarian function is impaired, follicle maturation is delayed, ovulation and the development of the corpus luteum are impaired. In the early stages of embryo development (6–8 weeks of gestation), it is impossible to save the pregnancy without hormonal support.
With a lack of thyroid hormones, a special hormone therapy is prescribed by a doctor. Until week 16, until the endocrine system of a child begins to develop independently, the pregnant woman must take prescribed hormones without fail.
If the pregnancy continues, another problem often arises, namely, that women do not form a normal labor activity for up to 42 weeks. The consequence of this is perenashivanie child in the womb, which is dangerous for both mother and child. Children in such situations may have birth trauma, damage to the central nervous system. For a mother, a prolonged pregnancy increases the risk of severe ruptures of the cervix and perineum.
The effect of hypothyroidism on pregnant
The hormones T3 and T4 are responsible for the metabolism and functioning of all organs in the body. With a decrease in their level, the process of formation of new proteins and the breakdown of spent proteins slow down. The process of excretion of decomposition products, which begin to accumulate in organs, muscles, skin and tissues, is impaired. The consequences can be varied:
• Decreased blood pressure.
• Increased blood cholesterol.
• Atherosclerotic vascular disease resulting in a heart attack or stroke.
If a woman has repeated spontaneous abortions (miscarriages), then she will definitely need to study the function of the thyroid gland. The reason for the miscarriage can even be mild subclinical hypothyroidism without a clinical picture.
Implications of hypothyroidism for the child
Probable complications in the fetus with hypothyroidism in the mother:
- miscarriage in the early period,
- malformations in a child,
- congenital primary hypothyroidism in a child,
- fading of pregnancy and fetal fetal death,
- impaired development of the fetal brain, and as a consequence, impaired intelligence in the child.
After birth, anemia, hypertension in a child may occur. Baby can be born with low body weight. In addition, children born with hypothyroidism are highly vulnerable to infectious diseases.
Replacement therapy for pregnant women with hypothermia
If replacement therapy for hypothyroidism has not been carried out, then when pregnancy occurs with uncompensated hypothyroidism, doctors recommend aborting the pregnancy at an early stage.
If a woman decides to keep the pregnancy, then hormone therapy is prescribed.
In replacement therapy, thyroid preparations are used, which gradually eliminate the symptoms of hypothyroidism and compensate for the insufficiency of thyroid hormones. Today, levothyroxine sodium (L-thyroxin, eutirox), a synthetic analogue of natural thyroxin, is used to treat patients with hypothyroidism. After absorption into the blood, this drug enters the liver and decomposes there with the formation of triiodothyronine, which, in turn, enters the tissue cells, having a positive effect on their growth, development and metabolic processes. Prescribe the drug for a long time, often for life. The dose to pregnant women is selected individually, it will exceed that which was before the pregnancy.
Protocol for the management of labor in hypothyroidism
As mentioned above, childbirth should take place in a narrow profile maternity hospital specializing in endocrine pathologies. Natural births with hypothyroidism occur without complications, cesarean section is performed only according to obstetric indications. The most frequent complication of the postpartum process is the weakness of the contractile activity of the uterus. In the postpartum period, due to a possible disturbance in the hemostasis system in hypothyroidism, hemorrhage prevention must always be carried out.
To streamline the process of childbirth, to prevent any medical violations, a protocol for management of labor has been developed. The protocol is a kind of standard for describing symptoms, identifying the causes, prescribing the correct treatment, observing the process of childbirth, therapeutic or surgical intervention of the doctor in the process of childbirth. Proper management of childbirth in hypothyroidism is the key to preserving health for a woman and her child.
After birth, the child must be screened for newborns to determine congenital hypothyroidism. Examine blood for TSH level: in children with normal weight and Apgar score more than 8 points for 5-6 days after birth, in children with low weight and Apgar score less than 8 points, as well as in prematurity - 7-10 day. And also appoint an ultrasound of the thyroid gland. If hormonal pathology is present, appropriate treatment is prescribed.
Types and causes of development
Hypothyroidism is primary (99% of cases) and secondary (1%). The first occurs due to a decrease in the production of thyroid hormones, which causes a decrease in its functionality. The cause of primary hypothyroidism is a disorder in the gland itself, and a secondary cause is damage to the pituitary or hypothalamus.
Primary hypothyroidism is divided into subclinical and manifest. Subclinical is called when the level of TSH (thyroid-stimulating hormone) is increased in the blood, and T4 (thyroxin) is normal. With manifest - TTG is increased, and T4 is reduced.
Norms of hormones in the blood:
- thyroid stimulating hormone (TSH): 0.4–4 mMe / ml, during pregnancy: 0.1–3.0 mIU / ml,
- thyroxin free (T4): 9.0–19.0 pmol / l, during pregnancy: 7.6-18.6 pmol / l,
- free triiodothyronine (T3): - 2.6–5.6 pmol / l, during pregnancy: 2.2–5.1 pmol / l.
Also, hypothyroidism is divided into congenital and acquired.
Causes of hypothyroidism:
- congenital malformations and anomalies of the thyroid gland,
- diseases that can lead to iodine deficiency (diffuse toxic goiter),
- thyroiditis (autoimmune, postpartum) - inflammation of the thyroid gland,
- thyroidectomy (surgery to remove the thyroid gland),
- thyroid tumors,
- iodine deficiency (with food or drugs),
- congenital hypothyroidism
- thyroid irradiation or radioactive iodine treatment.
Many pregnant women with hypothyroidism on the background of full compensation give birth in time and without complications. Cesarean section is performed only according to obstetric indications.
When hypothyroidism sometimes occurs such a complication in childbirth, as a weak labor activity. Delivery in this case can be either through the natural paths, or using a cesarean section (depending on the evidence).
In the postpartum period there is a risk of bleeding, therefore prevention is necessary (administration of drugs that reduce the uterus).
Possible complications of hypothyroidism for the mother and fetus
There is a risk of congenital hypothyroidism in the fetus. If the disease is detected in time, then it is easily amenable to correction with the help of substitution therapy.
- miscarriage (30-35%),
- weak labor activity
- bleeding in the postpartum period.
Possible complications of uncompensated hypothyroidism:
- hypertension, preeclampsia (15-20%),
- placental abruption (3%),
- postpartum hemorrhage (4-6%),
- small body weight of the fetus (10-15%),
- fetal abnormalities (3%),
- fetal fetal death (3-5%).
With timely and adequate treatment, the risk of complications is minimal. For a favorable course of pregnancy and fetal development, replacement therapy is required throughout the entire period of pregnancy. In case of congenital hypothyroidism in a pregnant woman, medical genetic consultation is necessary.
Statistical data taken from the site of the Federal Medical Library (dissertation: "Krivonogov M. Ye., Fetus in pregnant women with iodine-deficient diseases")
Some studies during pregnancy