Pregnancy and Nephritis.

Abstract

In spite of the well-known fact that nephritis will do harm on pregnancy, only few studies have been made on the subject from the functional point of view. Clinical picture of nephritis reveals great variety. Particularly it shows more complicating face at the time of pregnancy because of the influence of preg-nancy upon the renal physiology, and the close resemblance of the clinical signs between renal diseases and preeclamptic toxemia. Observations were made on the clinical cource and the renal function of the healed acute and the chronic nephritic patients during and after pregnancy. 1) The material of this study were 267 patients who were seen at Tokyo Metropolitan Police Hospital and Hospital of Tokyo University during 10 years since 1957; primigravida 258 cases of them with definite history of nephritis and rest of them, 9 cases with no history of it but revealed chronic nephritis after renal biopsy. 2) a) Pregnancy with "healed acute nephritic": 234 cases were classified as "healed acute nephritis" which revealed no proteinuria or hypertension and were considered to be curred by the time of the first examination at the obstetric clinic prior to 20 th week of pregnancy. Preeclamptic toxemia developed in 25 (10.7%) of 234 cases. Morbidity rate of this is about same with that of the pregnant without predisposing factors. However, the severe toxemia especially with early-onset developed frequently among these "healed acute nephritis" group, and many of them retained the increased proteinuria for a long time as a sequelae, and several cases of them determined finally as chronic nephritis by means of renal biopsy. It is suggested that clinically once-cured nephritis may have appeared again with the onset of toxemia, b) Pregnancy with chronic nephritis 33 cases of this series were classified pregnancy with chronic nephritis. 21 cases out of them revealed proteinuria and rest of them, 12 cases revealed both proteinuria and hypertension at the first examination. Morbidity rate of superimposed toxemia (blood pressure higher than 160 mmHg) in proteinuric-type nephritis (includes nephrotic syndrome) was as high as 30%. The foetal prognosis of this group was definitely poor. Before and during pregnancy, the renal function rather was surprisingly good in most of them (GFR more than 70 ml/min.) and it remained normal after delivery without relating to the occurence of toxemic symptoms. Though it seems to be that pregnancy does not affect nephritis, but as a matter of fact these cases often increased and retained proteinuria. In hypertensive-type nephritis, the renal function was not good generally before and during pregnancy (GFR under 70 ml/min.). The complication of toxemic symptoms was found frequently in these cases. Then it became impossible to continue pregnancy. After delivery, the renal function remained poor and some of them seemed to have developed the nephritic process with the circulatory disturbance of superimposed toxemia. Generally speaking, it is not advisable to be pregnant in this type of nephritis. 3) Finally, the prognosis of the mothers with chronic nephritis and that of their foetus largely depend greatly on the severity of the renal impairment existed before pregnancy. Author has an impression that safety level functionally is considered 70 ml/min., or more on the GFR. However, the complication of superimposed toxemia seems to be another factor to influence the coerce of pregnancy both on the mother and foetus and it further deteriorate the already-impaired function of the kidney. Apparently, foetal prognosis is poor but sometimes nephritic process may also develop to the mothers in such cases, especially when renal function was already poor before pregnancy (GFR under 70 ml/min.) 4) Summary : From the study of 267 cases of pregnant women, author suggests strongly to set a standard of the safety level at 70 ml/min, of GFR for the pregnancy complicated with nephritis, as it divides progn