Журнал «Здоровье ребенка» 6 (49) 2013
Вернуться к номеру
Congenital anomalies of kidneys quantity: frequency, etiopathogenesis, prenatal diagnostics, clinical
Авторы: Nikitina N.A., Starets E.A., Kalashnikova E.A., Galich S.R., Sochinskaya T.V. - Odessa National Medical University, Department of Propaedeutics of Paediatrics, Ukraine
Рубрики: Семейная медицина/Терапия, Педиатрия/Неонатология
Разделы: Справочник специалиста
Версия для печати
kidney anomalies, agenesis, aplasia
Since the 2nd half of the 20th century there has been noted a considerable increase of malformations, especially in developed countries. According to the data of WHO, they are revealed in 2,5-3% of newborn, approximately 1% makes up gene diseases, 0,5% - chromosome, and, on average, 1,5-2% fall to the share of congenital malformations, due to the adverse exogenous and endogenous factors.
In general, the incidence of registered newborns with genetic disorders in Ukraine is comparable to European figures.
The causes of 40 - 60 % of congenital malformations are unknown. 20 - 25% of the anomalies are more likely to be due to multifactorial causes that reflect the complex interaction of different small genetic defects and risk factors of the environment, 10 - 13% are associated with the influence of the external environment, 12 -25% are proved to have the presence of genetic causes.
The formation of malformations occurs mainly in the period of embryonic morphogenesis (3-10 weeks of pregnancy). At this, there may be an underdevelopment or excessive development of organs or their parts, lack of organs or body parts (agenesis), disposition or replacement of organs (dystopia), improper formation of this or that tissue (dysplasia). There distinguish double (multiple) and single malformations.
Congenital defects of the urinary system are referred to the most frequent anomalies, making up 35-40% of the defects of all organs and systems.
According to A.V. Lulko’set al. (1984), the quantity anomalies include:
- agenesis of one or both kidneys;
- third extra kidney;
- doubling kidneys, unilateral or bilateral.
Agenesis is the complete lack of kidney structures of one or both kidneys. Agenesis of the kidneys may be combined with uni- or bilateral absence of the ureters and urinary bladder.
According to MKB 10 there is Q60 Agenesis and other reducing renal defects.
The average frequency of unilateral agenesis, including the cases of aplasia, is 1 per 900 - 1500 births, bilateral agenesis occurs with the frequency of 3.5 per 10,000 births.
Etiologically, this defect is not homogeneous. More often it occurs sporadically. The increase of incidence of the given malformation is noted among children of mothers suffering from diabetes. Isolated agenesis of the kidney is the consequence of the violation of differentiation of nephrogenic blastema.
On diagnostics of fluid deficiency, particularly in the early periods of pregnancy, one always needs to search for kidney agenesis. Bilateral renal agenesis is accompanied by a symmetric form of intrauterine growth retardation of the child and fluid deficiency, which are clinical signs of progressive placental dysfunction. The correction of placental dysfunction of the given defect is usually ineffective. There is a high risk of miscarrying of pregnancy, including premature birth and stillbirth, caused by pre-natal death of the child.
Prenatal detection of the fatal defect of up to 22 weeks is an indication for termination of pregnancy on medical grounds in late pregnancy. In case of refusal from the termination of a pregnancy, as in the late diagnosis of defect, conservative obstetric tactic is used.
Agenesis of kidneys is often combined with the anomalies of genital organs, and it’s also an integral part of the known complexes of multiple congenital malformations.
Children with this pathology have characteristic facial dismorphism - protruded frontal bumps, deformed low located ears, wide flat nose, micrognathia, hypertelorism of eyes, epikant, puffiness of the face - "the face of Potter." Due to fluid deficiency and compression of the fetus almost 100% children with this disease are observed to have secondary hypoplasia of lungs and deformation of lower extremities and deformation of the lower extremities, excessive skin folding and increase of abdominal size. Almost half the children with kidney agenesis are prematurely born. The defect is lethal in children with agenesis of both kidneys, although there are described cases of life of children without kidney during 10-23 days.
Early manifestation of agenesis and aplasia of the kidneys is anuria. Symptoms of a unilateral agenesis and aplasia are absent. In bilateral aplasia the defect is lethal, in violation of the only kidney’s function the transplantation of the organ is recommended.
Prophylaxis - prevention of the impact of teratogenic factors in the first 2 weeks of pregnancy and the interruption of pregnancy in case of detection of ultrasonic picture of absence or aplasia of both kidneys.