EMBRYOPATHIES

From Big Medical Encyclopedia

EMBRIOPATYI (embryopathia,

singular; Greek embryon a uterine fruit, varodysh + pathos suffering, a disease) — the general name of diseases, malformations and morbid conditions, to-rye arise in the embryonal period under the influence of the adverse external factors influencing a germ. The inborn pathology connected with defeat of hereditary structures of gametes is carried to gametopathies <see).

The pathogeny of an embryopathy is difficult (see Malformations, the Teratogenesis). The first 2 weeks of pregnancy when there is an implantation of fetal egg, make the first critical period of an embryogenesis (see. Embryonic development). In this period under the influence of adverse exogenous effects there can occur death of a germ and pregnancy is interrupted or thanks to high regenerator ability of blastomeres of an embryo it continues to develop. In the second critical period (from 3 to 6 weeks of pregnancy) the embryo is extremely sensitive to exogenous influences in connection with an active differentiation of cells and the raised metabolism. In these durations of gestation the teratogenic effect of environmental factors, including and medicines is most often shown. Except duration of gestation matter elective affinity of a disturbing factor to certain fabrics of a germ and character of the factor.

To the exogenous factors promoting emergence E., belong inf. agents, preferential viruses, napr, a virus of a rubella (see the Rubella), a cytomegalovirus (see the Cytomegaly) \chemical substances (nek-ry pharmaceuticals, poisons, etc.); physical impacts, napr, ionizing radiation (see). Internal causes more often are diseases of endocrine system of the pregnant woman, napr, the diabetes mellitus leading to development of a diabetic embryopathy (see a diabetes mellitus).

The embryopathies caused by viruses. Krasnushny, or rubeo-lyarny, AA. arises at a virusemia.

For the first time the teratogenic effect of a virus of a rubella for the person was established by the Australian ophthalmologist Gregg (N. M of Gregg), to-ry in 1941 described a complex of inborn malformations at children, mothers to-rykh had a rubella to time of pregnancy. Krasnushny E. it is characterized by Gregg's triad — damage of eyes, an acoustic organ and heart. Also defeat of dental germs and c is often observed. N of page. Especially typical damages of eyes are a cataract (see), edges in 80% of cases there is bilateral, and a microphthalmia. The hypoplasia of a ciliary body, a hydrophthalmia (see), narrowing of a venous sine of a sclera (a shlemmov of the channel) with the phenomena of glaucoma and a pigmental pseudo-retinitis can be noted. Defeat of an acoustic organ is shown by disturbance of ossification of a labyrinth, differentiation of a kortiyev of body and semicircular channels, deafness. Damage of heart usually has character of inborn defects, among to-rykh a thicket the open arterial channel, a stenosis and a hypoplasia of a pulmonary trunk, a stenosis of an aorta, defect of an interventricular partition, Fallo's tetrad meet (see Heart diseases inborn). The nanocephalia (see) in the form of a hypoplasia of big hemispheres or separate shares of a brain is sometimes observed, is more often than occipital.

There are data on teratogenic influence of a cytomegalovirus, a virus of a herpes simplex, measles, epidemic parotitis, hepatitis B, poliomyelitis, chicken and natural pox.

The embryopathies caused by chemicals. Among them special value have E., caused by various medicines. In particular, use in early durations of gestation of non-steroidal anti-inflammatory drugs (e.g., indometacin) renders embriotoksichesky (a resorption of a germ) and teratogenic action (a hypoplasia of a left ventricle of heart, defect of a partition of heart, phrenic hernia). During the use of corticosteroid drugs (glucocorticoids) teratogenic defeat is shown at the newborn in the form of a crevice of a hard palate, a cataract, malformations of extremities, etc. Antituberculous remedies (an isoniazid, Tubazidums) appointed in the first trimester of pregnancy can also cause a number of considerable damages to a germ (an anencephalia, an ectopia of a bladder, an atresia of an anus, splitting of vertebrae, defects of partitions of heart, a clubfoot). Also anticonvulsant, antineoplastic means, nek-ry antibiotics and some other pharmaceuticals have teratogenic effect.

The Talidomidny embryopathy (Videmann's syndrome) is connected with reception on 4 — the 10th week of pregnancy of a thalidomide. This embryopathy is shown by dismeliya of various look, to-rye are combined with other inborn defects of various bodies and systems (it is detailed see the Thalidomide).

Alcoholic E. develops more often at children, mothers to-rykh suffer from an alcoholism (see). At alcoholic E. the small-for-date fetus, a nanocephalia, a microphthalmia, a micrognatia, a ptosis, Epi-kantus, a hypertelorism are characteristic. Inborn heart diseases (defect of an interventricular partition) and other bodies (a dysplasia of kidneys) can be also observed.

The embryopathies caused by endocrine diseases of mother. In a crust, time diabetic E. Bolshinstvo of researchers is most studied consider that inborn malformations at children, mothers to-rykh suffer from a diabetes mellitus, meet twice more often than at children of healthy mothers. The leading value in a pathogeny diabetic E. has insufficiency of insulin at mother and lability of a day-night rhythm of glucose at the pregnant woman with a diabetes mellitus. Insufficiency of insulin causes oppression of energy resources in rudiments of bodies of an embryo that leads to developing of inborn malformations. Characteristic for diabetic E. the complex of inborn malformations in the form of a caudal dysplasia (absence or a dysplasia of a sacrum and tailbone, lumbar vertebrae and femurs) is. The caudal dysplasia can be combined with changes of a spinal cord and secondary deformations of the lower extremities. Also malformations of urinogenital bodies, hearts (defect of interventricular and interatrial partitions, Fallo's tetrad), c are observed. N of page (anencephalia, acrania), atresia of an anus and rectum.

The embryopathies caused by physical factors. Among them the greatest value has radiation E., edges can develop at a fruit if the woman was affected by ionizing radiation (see) during the first and second trimesters of pregnancy. Are available this, testimonial that radiation in a dose St. 15 — 20 r leads to emergence radiation E., for a cut the nanocephalia, hydrocephaly, a cataract, a coloboma, disturbance of development of bones of a skull are characteristic.

Methods of a research — see. Antenatal pathology.

Prevention. Because considerable part E. arises during the first trimester of pregnancy, it is necessary that pregnant women, especially during this period, avoided contact with sick viral infections, use without emergency of various medicines and other adverse effects. At the pregnancy proceeding against the background of a diabetes mellitus it is necessary to provide its permanent compensation.

146 EMBRYOTOMY


See also Antenatal protection of a fruit.

Bibliography: Kiryushchenkov A. P.,

Influence of harmful factors on a fruit, page 104, M., 1978; Pathological anatomy of diseases of a fruit and the child, under the editorship of T. E. Ivanovo and B. S. Gusman, t. 1, page 10, 363, M., 1981; The Teratology of the person, under the editorship of G. I. Lazyuk, page 24, M., 1979; Naga-d J. Congenital alkyl mercury poisoning (congenital minamata disease), Paediatrician, Y. 6, p. 58, 1977; Haumont D., Le nouveau — pyo de mfere diabyotique, Rev * P£diat., t. 19, p. 369, 1983; Paediatric pathology, ed. by C. L. Berry, B. — N. Y., 1981; Shepard T. H. Detection of human teratogenic agents, J. Pediat., v. 101, p. 810, 1982. T. E. Ivanovskaya.

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