What is congenital malformation? You will learn the answer to this question from the submitted article. In addition, we will tell you about what types of defects exist, why they develop, and so on.
General Information on Birth Defects
Defect is an abnormal development, as well as the totality of any deviations from the normal (standard) structure of the human body that arise in the process of intrauterine development (less often postpartum).
As a rule, such changes are formed under the influence of various internal and external factors (for example, hormonal disorders, heredity, inferiority of germ cells, viral infection, ionizing radiation, lack of oxygen, etc.). From the second half of the twentieth century, experts began to note a significant increase in pathological changes. Most congenital malformations occur in people living in developed countries.
Probable Causes
In 40-60% of people, the causes of these deviations are unknown. A term that sounds like a "sporadic birth defect" is applied to such patients. This expression denotes an accidental occurrence or an unknown cause, as well as a reduced risk of recurrence in a future generation.
For 20-25% of people, congenital malformations are formed from a "multifactorial" cause, that is, a complex interaction of genetic defects (usually small ones) or environmental risk factors . 10-13% of anomalies are associated only with environmental exposure. And only 12-25% of defects have exclusively genetic causes of development.
So, we will consider in more detail why certain people have congenital malformations.
Teratogenic factors
The effect of such factors depends on their dosage. Differences in teratogenic effects in different species can be associated with the characteristics of metabolism, absorption, the ability of a substance to penetrate the placenta and spread throughout the body.
The most popular and studied teratogenic factors
Malformation is most often observed in those who are exposed to the following effects:
- Infectious diseases that are transmitted from mother to fetus. A number of viral diseases transferred during the gestation of the child, such as mumps, rubella, or inclusion cytomegaly, may well contribute to the development of the disease.
- Alcohol. Of particular importance is the alcoholism of the parents, or rather, the mother. Drinking alcohol during pregnancy can easily lead to fetal alcohol syndrome.
- Ionizing radiation. Exposure to radioactive isotopes, as well as x-rays, can have a negative effect on the genetic apparatus. It should also be noted that radiation (ionizing) has a toxic effect. This fact is the cause of most congenital anomalies.
- Medications. To date, there are no such medicines that would be recognized as completely safe for the fetus, especially in the first 2 trimesters of pregnancy.
- Nicotine. Smoking expectant mothers (during pregnancy) can quite easily lead to the fact that the child will lag behind in physical development.
- Nutrient deficiencies. Lack of a number of nutrients (e.g. iodine, myo-inositol, folate, etc.) is a proven risk factor for congenital heart defects and neural tube defects.
Consider such a common anomaly as heart valve disease, in more detail.
Heart defects
Heart disease is a pathological change in the valves, large intrathoracic vessels, as well as the septum of the heart, as a result of which the normal movement of blood is disturbed. It should be noted that such deviations can be either acquired or congenital.
Most often, valvular heart defects occur due to the excessive struggle of the immune forces of the human body with harmful microorganisms that have penetrated into it. The treatment of this deviation is reduced to the replacement of natural, but damaged valves, by artificial means of surgical intervention.
When a defect develops
This pathological phenomenon (any type) is most often formed during the period of embryonic morphogenesis (that is, at the 3-10th week). This fact is due to the fact that it is at this time that the processes of reproduction, differentiation, migration and cell death are disrupted. Such phenomena occur at the interstitial, intracellular, interorgan, extracellular, organ and tissue levels.
Existing types
Congenital malformation is the broadest category that includes completely different conditions: from minor physical abnormalities (for example, large moles, birthmarks, etc.) to serious disorders of individual systems (for example, heart valve disease, limb defects, etc.). There are also combination anomalies that affect several parts of the body at the same time. Metabolic defects are also considered congenital malformations.
In medical practice, there are three main types of congenital malformations:
- congenital metabolic errors;
- congenital physical abnormalities;
- other genetic defects.
Frequency of occurrence
Long-term studies of congenital anomalies have shown that a particular fetal malformation manifests itself with a certain frequency depending on the gender of the child. For example, the club-shaped foot and pyloric stenosis are most common in boys, and congenital dislocation of the hip in girls.
Among those children who were born with one kidney, there are more representatives of the stronger sex. It should also be noted that most often such abnormalities as the excess number of ribs, teeth, vertebrae and other organs are found among newborn girls.
List of malformations
Today, there are a huge number of malformations. Most often, they are detected during an ultrasound examination of the mother. If the anomaly is serious enough, then the woman is offered to terminate the pregnancy. This is due, first of all, to the fact that a born child will be in danger throughout his life and will feel inferior (depending on the type of anomaly).
Let's look at together what developmental defects exist:
- aortic malformation;
- jejunum atresia;
- agenesis of the lung;
- acrania;
- bilateral renal agenesis ;
- anencephaly;
- congenital dislocation of the hip;
- unilateral renal agenesis;
- esophageal atresia;
- congenital cesspool;
- albinism;
- VACTERL association;
- aplasia of the lung;
- cleft palate;
- atresia of the anus;
- clavate foot;
- Down's disease;
- congenital cretinism;
- congenital megacolon;
- congenital heart defects;
- hydrocephalus;
- hernias;
- hypoplasia of the lung;
- esophageal diverticulums;
- syndactyly;
- X-chromosome polysomy;
- Meckel's diverticulum;
- Patau syndrome ;
- cleft lip;
- polythelium;
- Klinefelter's syndrome;
- cryptorchidism;
- genital defects;
- clubfoot;
- Klippel-Feil syndrome;
- megacolon;
- feline scream syndrome;
- microcephaly;
- Shereshevsky-Turner syndrome;
- underdevelopment of the femur and tibia;
- fetal alcohol syndrome ;
- omphalocele;
- spinal hernia;
- fibrodysplasia;
- pyloric stenosis;
- polydactyly;
- Edwards syndrome ;
- cyclopia;
- craniocerebral hernia;
- bladder exstrophy;
- epispadias;
- ectrodactyly.
To summarize
As you can see, there are quite a few congenital malformations that occur in the fetus in the prenatal period of development. To avoid the occurrence of such anomalies in their child, future parents should avoid exposure to factors contributing to their education. Thus, it is recommended that expectant mothers and fathers refuse to drink alcoholic beverages 6–9 months before conception, and also not to consume them during pregnancy (for women). In addition, you should quit smoking, avoid those places where there may be ionizing radiation, do not take medications that are not prescribed by a doctor, more likely to be in the fresh air and take all the necessary vitamins and minerals.