When it comes to intrauterine growth retardation, then, usually, we mean the totality of the most significant signs of those children who at birth had a 10% weight deficit from the expected. Sometimes such children are described as too small for their gestational age, with a nutritional defect, or impaired maturation. This pathology has approximately 1 in 10 newborns; as a result, they have an increased risk of developing neurological disorders, congenital malformations, meconium aspiration, hypoglycemia, hypocalcemia and respiratory failure syndrome. It is observed more often in representatives of the black race than in whites.
Causes of intrauterine growth retardation
К The factors , that cause such disorders include:
- chromosomal abnormalities (10%);
- intrauterine infections (rubella, cytomegaly , toxoplasmosis, syphilis);
- poor maternal health (high blood pressure, kidney and heart disease);
- mother's nutrition and its socio-economic status;
- mother consuming alcohol; , drugs, smoking;
- placental insufficiency;
- мmultiple pregnancy (twins, triplets).
Small fruits that weigh less than 500 g rarely survive, and those that weigh 500 to 1000 g can survive with special care. Newborns can be small due to intrauterine growth retardation during the full gestation period. But they can also be small due to premature birth
The main growth promoter before and after birth is the insulin-like growth factor-1 (IGF-I), which is characterized by mitogenic and anabolic effects. Embryonic tissues produce IGF-I, and its serum level changes with fetal growth. Mutations of the IGF-I gene lead to intrauterine growth retardation, and this delay also continues after birth. Unlike the prenatal period, the postnatal period depends on growth hormone (GH).Mutations in the gene that encodes the synthesis of growth hormone receptor leads to Laron dwarfism, which is characterized by stunted growth, mid-face hypoplasia, blue sclera and limited elbow extension.
Nutritional deficiencies. There is evidence that poor nutrition of the mother during pregnancy leads to low birth weight and malformations.
Hypoxia. Hypoxia causes birth defects in many types of experimental animals. Babies born high above sea level are usually lighter and smaller than those born closer to sea level. In addition, women with cardiovascular insufficiency often give birth to small children, but mainly without significant congenital pathologies.
Heavy metals. Several years ago, researchers from Japan noticed that many mothers, whose food consisted mainly of fish, gave birth to children with multiple neurological symptoms that resembled cerebral palsy. Further research revealed that the fish contained a very high level of organic mercury compounds. Many of these mothers themselves did not find any symptoms of mercury lesions, indicating a hypersensitivity to the fetus than the mother. A similar incident occurred in Iraq, where several thousand children were struck after their mothers consumed grain treated with mercury-containing fungicides. Lead leads to an increase in abortion rates, stunting and neurological disorders.