Congenital Hypothyroidism: Causes, Symptoms & Treatment

Congenital hypothyroidism is a form of hypothyroidism. It is caused by a disorder during embryonic development.

What is congenital hypothyroidism?

Congenital hypothyroidism is a form of hypothyroidism. In medicine, congenital hypothyroidism also goes by the name connatal hypothyroidism or congenital hypothyroidism. It is a special form of hypothyroidism. We talk about hypothyroidism when the thyroid gland produces too few hormones. Due to the lack of hormones, all metabolic processes in the body are slowed down, which in turn has a negative effect on the performance of those affected. In addition, the thyroid hormones T3 and T4 are important for human development and promote growth. If hypothyroidism is already present in babies because it is congenital, there are significant developmental limitations. These include negative impairment of brain maturation, which in turn results in neurological damage. Bone growth is also delayed and affected children suffer from slowed reflexes and react apathetically. Congenital hypothyroidism is seen in one in 5000 newborn children. This makes it one of the most common metabolic diseases that are already congenital. In girls, congenital hypothyroidism is twice as common as in the male sex.

Causes

Congenital hypothyroidism occurs due to defective development of the thyroid gland. Thus, during embryonic development, too little or even no thyroid tissue is formed that is functional. It has not yet been possible to determine the cause of these abnormalities. In some individual cases it was possible to prove the existence of gene mutations. In these cases, the genes played an extremely important role in the development of the thyroid gland. In other affected individuals, the thyroid gland is not in its usual anatomical position, resulting in limitations of its functions. A rare cause of congenital hypothyroidism is faulty production of thyroid hormones. In addition, there may be an insensitivity of the cells to the hormones. This causes them to react incorrectly to the hormone signals. Sometimes congenital hypothyroidism lasts only temporarily. In such cases, it is triggered by the transfer of drugs given to the mother or blocking antibodies. Reasons include a deficiency of iodine or iodine overdose.

Symptoms, complaints, and signs

Despite the extremely important role of thyroid hormones in the development of human organs, congenital hypothyroidism does not initially show any noticeable symptoms. Only later do nonspecific symptoms develop. For example, affected children often suffer from jaundice, which lasts about two weeks. Furthermore, the babies drink poorly and exhibit only a weak sucking reflex. Their reflexes are also weakened. A conspicuous feature is an enlarged tongue, which is called macroglossia. Another symptom of congenital hypothyroidism is constipation. When the affected child reaches toddler age, his decreased height is noticeable. Bone and teeth age do not correspond to the child’s age and are underdeveloped. In addition, children are mentally slow to respond and show decreased intelligence. Other conceivable sequelae of congenital hypothyroidism may include hearing loss and speech disorders. If congenital hypothyroidism remains untreated, the child is at risk of cretinism due to the lack of thyroid hormones. This results in irreparable damage to the central nervous system. Because of this, affected children suffer from skeletal deformities, short fingers, deafness, or open fontanelles.

Diagnosis and course

Early diagnosis of congenital hypothyroidism is crucial for the further development of affected children. In most countries, diagnosis takes place during screening examinations in the neonatal period. In Germany, doctors determine the level of the hormone thyrotropin (TSH) for this purpose during a legally prescribed hypothyroidism screening. In the case of deficient thyroid hormone production, this hormone rises sharply. The examination takes place between the 36th and 72nd hour of life.A few drops of blood are taken from the heel. In the case of congenital hypothyroidism, the T3 and T4 values are lowered because the hormones are not produced in sufficient quantities. If congenital hypothyroidism is detected during the first two weeks of life, it can be treated excellently and takes a positive course. At a later age, only minor differences in intelligence, school performance and neurophysiological tests can be observed compared to healthy children. If treatment takes place at a later stage, there is a risk of limitations in intelligence despite normal physical development.

When should you see a doctor?

If a newborn has congenital hypothyroidism, he or she will develop various unusual symptoms after birth. Based on these, an expert pediatrician can infer the condition. Further examinations usually verify the initial diagnosis. The mother provides thyroid hormones to the child until birth. Without routine thyroid screening, which has been performed since 1978, physicians would not necessarily notice congenital hypothyroidism right away. Congenital hypothyroidism requires lifelong treatment. In the beginning, the visit to the doctor is necessary weekly or fortnightly. Later, it is sufficient to schedule a routine doctor’s visit every quarter, because this malfunction is potentially dangerous. The deficiency of thyroid hormones must be compensated. If this is not done, further sequelae are to be expected. In some cases, the thyroid dysfunction is only temporarily noticeable. In most cases of congenital hypothyroidism, the dysfunction lasts for life. Thanks to its far-reaching consequences for the organism, hypothyroidism must be treated by administering the missing thyroid hormone. With correct dosage, the child is fully capable of development. Crises are not to be expected. However, they may occur – for example, if the thyroid hormone is excreted by diarrheal diseases before being absorbed into the organism. Therefore, a visit to the doctor is advisable for all diseases that can lead to such results.

Treatment and therapy

Therapy for congenital hypothyroidism should be started as early as possible because the impairment of the nervous system may not be reversible. Even waiting for test results may cause unnecessary delay. For this reason, treatment must begin immediately after the blood sample is taken if the screening results are positive. The most important part of the therapy of congenital hypothyroidism is the substitution of the hormone T4 (thyroxine) with L-thyroxine. The administration is started with a low dose, which can be gradually increased in the further course of treatment. Once the patient reaches a certain hormone concentration, it is eventually maintained. The treatment of congenital hypothyroidism is intended to normalize the TSH level within the blood and achieve freedom from symptoms. An important part of the therapy is constant monitoring of the hormone level. In this process, the physician checks the normal functional status of the thyroid gland.

Outlook and prognosis

In many cases, this disease is discovered relatively late, so treatment can also be initiated late. Patients may suffer from jaundice in the process. Likewise, there is a markedly decreased intake of fluid in babies, which can have a very negative effect on the patient’s development and overall health. Furthermore, the reflexes of those affected are weakened in most cases. It is not uncommon for those affected to also suffer from constipation and thus a significantly reduced quality of life. Especially for the parents, this disease represents a strong psychological burden, so that they are also dependent on treatment. The intelligence of those affected is also significantly reduced by this disease, so that those affected are dependent on the help of other people in their lives. Furthermore, speech disorders and hearing loss also occur. In the worst case, complete deafness also occurs in the patient. A causal treatment of this disease is usually not possible. Some symptoms can be reduced, but there is no complete cure.Whether there is a reduction in life expectancy due to the disease cannot be predicted in general.

Prevention

The exact causes of congenital hypothyroidism are not known. For this reason, there are no effective preventive measures.

Follow-up

Congenital hypothyroidism cannot be completely cured, which is why follow-up care focuses on everyday support and prevention of complications. To what extent medical follow-up becomes necessary depends on the extent of the symptoms. In principle, it can be stated that early treatment leads to comparatively few symptoms. Newborn screening points to the non-functioning thyroid gland at an early stage. The number of hormones can be clearly determined by blood test. This is also continuously monitored in the subsequent period. Doctors can derive a clear drug therapy from this. The last consists of administering the hormone T4. Consequential diseases can be prevented in this way. Parents and close relatives play an important role in the first years of life. The child’s zest for action should be encouraged. Sports activities, walks and daily hours in the sunlight improve well-being. Unfortunately, congenital hypothyroidism is not always treated early. This results in the well-known complications. These make a normal life almost impossible. Among other things, the senses and mental abilities are insufficiently developed. Patients are not infrequently placed in nursing homes for the rest of their lives and require care. A high degree of disability often stresses parents, who in turn seek help in psychotherapy.

Here’s what you can do yourself

When congenital hypothyroidism occurs, it is inevitable to see a doctor and receive a hormonal preparation to stimulate the thyroid gland, because ignoring this disease can cause severe mental or nervous consequences. Especially in certain phases of growth, the missing hormone is very important for development. Anything that also has a positive effect on well-being is supportive: long walks in the fresh air, soaking up sunlight, exercising and a healthy diet. An underactivity of the thyroid gland makes you listless, here it is important to continue activities. It is not uncommon for hypothyroidism to lead to depression, so well-being is very important in hypothyroidism. Also, it should be checked if the body lacks vitamins, because vitamin deficiency often occurs additionally in people with metabolic problems. Thyroid levels are checked during blood tests and must be monitored at regular intervals so that hormone administration can be perfectly adjusted to the body. It is also advisable to have an ultrasound with an internist to see if there are any abnormalities in the thyroid gland. The earlier hypothyroidism is diagnosed, the fewer consequences it leaves in the affected person and therapy can be started.