The kidneys are formed in the fetus in the first trimester of life, and already the fourth month are able to produce urine, but their function until the birth, it is irrelevant and useless, because in period of fetal life has any exchange of fluids as an intermediary the placenta.
E 'so easily understood as a fetus, which lacks both kidneys, for example, for a dell'abbozzo embryonic malformation, can live and grow regularly in the uterus for the duration of gestation, shortly after the birth of the baby, however, the situation changes rapidly lead to death.
Renal function in newborn babies is the same thing than in adults, is just a little 'more' rough ', because at birth the kidneys are not yet perfect, but slightly immature, both in terms of the structure is to regard to functional capacity. The glomerular filtration and tubular reabsorption are limited and consequently the elimination of waste risulla decreased, and for this reason and to have a normal cleansing of the blood, the baby needs a larger amount water, which is then largely eliminated in the urine not concentrated, but given more frequently and in greater quantities.
The first urination usually occurs within the first twenty-four hours of life, and later, with the initiation of the amount of liquid ingested is increasing day by day and hand in hand urinary elimination occurs more frequently, up to occur fifteen to twenty times a day.
Generally it is estimated that eliminates the small child in one day, about two-thirds of the ingested fluids . The urine of infants reflects the renal function is not perfect: it contains, in fact, protein (albumin), white cells and red blood cells within two weeks these elements disappear, and the composition of urine to normal.
The disorders of the urinary BABIES IN CHILDREN: The persistence of albumin or elements of the blood, should not be underestimated, but always considered very carefully because it could be indicative of a disturbance of renal function. In very young child, and in particular in the newborn is not easy to diagnose the presence of alterations in the apparatus urinate because the symptoms are almost always very distinctive and often masked by a stunted growth, a poor appetite, from a general suffering, which may distract attention from the real cause of doctor della malattia. In molti casi, infatti, solo l'esame delle urine e l'esame del sangue riescono a far luce e a spiegare sintomi non chiari e senza caratteristiche particolari.
Il rene del neonato non è quasi mai sede di infezioni batteriche e nemmeno di reazioni di tipo allergico, quali ad esempio la glomerulonefrite, mentre sono relativamente frequenti stati infiammatori e gli ostacoli all'eliminazione di urina dovuti alla presenza di malformazioni sia del rene sia delle vie urinarie, comprendendo in queste ultime in ordine di successione anatomica: gli ureteri, la vescica, l'uretra e il meato urinario. Le infiammazioni delle vie urinarie dei bambini neonati sono purtroppo ancora poco chiaramente definite dal punto di vista dell'origine; se spesso rappresentano an event secondary to an obstructed urine flow, type of malformation due to injury, many times they are expressions of an infection that is localized in normal kidneys shortly before birth or in early life. Such situations are realized in the prenatal period, such as pei the ingestion of infected amniotic fluid, and after birth may be the result of mastitis in the mother, as in this case the small sucking milk contaminated by pathogens, which going in circles to reach the kidney.
