Congenital defect - what is it? You will learn the answer to the question posed from the presented article. In addition, we will tell you about what types of defects exist, why they develop, and so on.
General information about birth defects
A defect is an abnormal development, as well as a set of any deviations from the normal (standard) structure of the human body that occur 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.). Since 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 of occurrence
In 40-60% of people, the causes of these deviations are unknown. A term is used for such patients, which sounds like a "sporadic birth defect." This expression means randomoccurrence or unknown cause, and a reduced risk of recurrence in future generations.
For 20-25% of people, congenital malformations are formed from a “multifactorial” cause, that is, a complex interaction of genetic defects (often small ones) or environmental risk factors. 10-13% of anomalies are associated only with environmental influences. And only 12-25% of defects have exclusively genetic causes of development.
So, let's take a closer look at why certain people have congenital malformations.
Teratogens
The effect of such factors depends on their dosage. Differences in teratogenic effects in different biological species may be associated with the characteristics of metabolism, absorption, the ability of the substance to penetrate the placenta and spread throughout the body.
The most popular and studied teratogenic factors
The malformation is most commonly seen in those exposed to the following:
- Infectious diseases that are transmitted from mother to fetus. A number of such viral diseases suffered during childbearing, such as mumps, rubella, or inclusion cytomegaly, may well contribute to the development of the defect.
- Alcohol. Of particular importance is the alcoholism of parents, or rather, mothers. Drinking alcohol during pregnancy can easily lead to fetal alcohol syndrome.
- Ionizing radiation. Exposure to radioactiveisotopes, as well as x-rays can have a negative impact on the genetic apparatus. It should also be noted that radiation (ionizing) also has a toxic effect. This fact is the cause of most congenital anomalies.
- Drugs. 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 by mothers-to-be (during pregnancy) can quite easily cause the child to lag behind in physical development.
- Nutrient deficiencies. Nutrient deficiencies (eg, iodine, myo-inositol, folate, etc.) are a proven risk factor for congenital heart disease and neural tube defects.
Let's 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 walls of the heart, resulting in disruption of the normal movement of blood. It should be noted that such deviations can be both acquired and congenital.
Most often, valvular heart disease occurs due to excessive struggle of the immune forces of the human body with harmful microorganisms that have penetrated into it. The treatment for this deviation is to replace natural but damaged valves with artificial ones through surgery.
Whenvice 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 intertissue, intracellular, interorgan, extracellular, organ and tissue levels.
Existing types
Congenital malformation is the broadest category, encompassing conditions ranging from minor physical anomalies (such as large moles, birthmarks, etc.) to major systemic disorders (such as valvular heart disease, malformations of the extremities, and etc.). There are also combination anomalies that affect several parts of the body at the same time. Metabolic defects are also considered birth defects.
In medical practice, there are three main types of birth defects:
- inborn errors of metabolism;
- congenital physical anomalies;
- other genetic defects.
Frequency of occurrence
Long-term studies of congenital anomalies have shown that one or another malformation of the fetus manifests itself with a certain frequency, depending on the sex of the child. For example, clubfoot and pyloric stenosis are most common in boys, while congenital dislocation of the hip is most common 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 anomalies asexcess 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 all his life and feel inferior (depending on the type of anomalies).
Let's explore together what malformations exist:
- aortic defect;
- jejunal atresia;
- lung agenesis;
- acrania;
- bilateral renal agenesis;
- anencephaly;
- congenital dislocation of the hip;
- unilateral renal agenesis;
- esophageal atresia;
- congenital cesspool;
- albinism;
- VACTERL association;
- lung aplasia;
- wolf mouth;
- anus atresia;
- clubfoot;
- Down's disease;
- congenital cretinism;
- congenital megacolon;
- congenital heart defects;
- hydrocephalus;
- hernias;
- lung hypoplasia;
- esophageal diverticula;
- syndactyly;
- X-chromosome polysomy;
- Meckel's diverticulum;
- Patau syndrome;
- hare lip;
- polytelia;
- Klinefelter syndrome;
- cryptorchism;
- defects of the genital organs;
- clubfoot;
- Klippel-Feil syndrome;
- megacolon;
- cat cry 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.
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 that contribute to their education. Thus, expectant mothers and fathers are advised to stop drinking alcoholic beverages 6-9 months before conception, and not to use them during pregnancy (for women). In addition, you should quit smoking, avoid places where there may be ionizing radiation, do not take medications that are not prescribed by a doctor, be outdoors more often and take all the necessary vitamins and minerals.
