by Julius H. Hess, M.D.
Small or larger hemorrhages in the kidney capsule are frequent, but extensive extravasations are rare. Minute hemorrhages on the renal surfaces are common. In the kidney substance hemorrhages are most commonly found at the apex of the pyramids and in the medulla. Besides this zone of predilection there is another at the junction of the cortex and the medulla. Here there are not always hemorrhages but markedly engorged vessels (vanae et arteriae arciformes). Hemorrhages occur more often between the urinary tubules than in them.
Uric-acid infarcts are found as yellowish granules in the kidney pyramids of prematures, still-born or perishing after a few days of life. Hemorrhages are usually present also in the same regions. Bile pigment is precipitated in the kidney in the same areas in which there is a predilection for hemorrhage.
That cylindruria and albiminuria may be present without gross demonstrable pathological change was mentioned before. The transition from physiological to pathological albuminuria is not abrupt and the instance of severe albuminuria is infrequent.
Observations have been so few in the cases of nephritis in newly born prematures that an exact clinical picture has not been established. Quite frequently one finds parenchymatous or fatty degeneration of the kidneys following toxic or infectious conditions. Perhaps the most outspoken form of nephritis in the new born is the syphilitic. An interesting question is the influence of nephritis and eclampsia in the mother on the kidneys of the infant. One commonly sees cases where the infant is unaffected and the urine retains its normal character, sometimes even when the premature shows eclamptic symptoms. At times there may be the findings of a well-marked hemorrhagic nephritis which clears up within a few weeks. Infrequently the infant may show congenital edema and ascites. The presence of "hydrops fetalis universalis" has been shown to have some relation to the presence of nephritis during pregnancy, with well-marked renal pathology, causing still birth or premature birth with death in a few days.
Shrunken kidneys have been demonstrated in the infant following chronic nephritis in the mother.
A relatively large portion of the cases of nephritis in the new born have been ascribed to infectious processes. Thus Mensi  examined 17 nephritic infants, ten to fourteen days old, and based the condition on infections secondary to the diseases of the respiratory and alimentary tracts.
The analogue of classical eclampsia in the mother is very seldom seen in newly born infants. These may show no untoward symptoms or may be prematurely born dead, or if alive succumb in a few days from degeneration of the organs, hemorrhages, or nephritis. Convulsions in infants born of eclamptic mothers are quite rare. Esch , in 1910, was able to collect only 32 cases from the literature and his own experience. The convulsions appear in the first few days of life, sometimes a few minutes after birth, usually before the end of the second day. Involvement of the eye muscles is usually first noted, then cyanosis appears, followed by tonic and clonic spasms of the body musculature. The convulsions last but a few seconds, sometimes several minutes. The severity of the eclampsia in the mother seems to have no influence on the frequency of appearance of convulsions in the infant. If the children survive the first few days the prognosis is relatively good. The treatment is to force fluids by mouth, per rectum, subcutaneously or intravenously, in order to dilute the circulating toxins.
We have experienced severe toxemia, as evidenced by stupor and other nervous manifestations, in both premature and full-term infants fed on eclamptic and nephritic mothers' early breast milk. To avoid this catastrophe it has become our rule to examine the infants very carefully for toxic symptoms and in their presence to feed all such prematures human milk obtained from healthy women, during the first few days or weeks of life.
The appearance of an infectious process in the urinary tract, as pyelocystitis, is as possible in the newly born as in older nurslings. Although general infections appear relatively easily in the first few days of life, nevertheless, clinical symptoms are often lacking. The presence of chills, fever, and sweats, as noted in older children, is seldom observed in the first few days of life, so that the diagnosis is only made by urinary examination, disclosing blood, albumin, pus cells in large numbers and not infrequently colon bacilli.
Pushing of fluids and the administration of potassium citrate to the point of positive alkalinization of the urine are the only therapeutic measures applicable to the premature.
 Rev. di clin. Ped., 1903, No. 8.
 Arch. f. Kinderh., 1909, 88, 60.