Some aspects of renal function in toxaemia of pregnancy. As seen in Kenyatta National Hospital and Pumwani maternity Hospital, Nairobi

Abstract

Over a period of seven months, 77 patients wi th preeclampsia (toxaemia of pregnancy) and 47 women having normal pregnancy were studied and compared. It was found that pre-eclampsia was a condition of the young primigravida (mean age 24.6 ± 0.45 years) and occurred generally during the last few weeks of gestation (median gestational age 36 weeks) The mean systolic blood pressure was significantly higher among pre-eclamptics (153.81 ± 1.22 mmHg) compared to that of the controls (111:67 ± 1.24 rnrnHg)P s 001. Significantly higher diastolic blood pressures were also noted in pre-eclamptics (mean 101.07 ± 0.79 mmHg) compared to controls (mean 70.83 ± 0.98 mmHg), P ~001. Most of the cases had oedema of varying severity. Only three controls had mild oedema probably due to partial obstruction of the venous return by the gravid uterus. All the cases had mi ld to severe proteinuria but no proteinuria was noted in the controls. Serum sodium levels tended to be lower (mean 132.5 ±0.3 mmol/l) in the pre-eclamptic as compared to that of the controls (mean 135.7 ± 0.65 mmHg), P -<001.

Serum potassium levels were within normal limits though generally higher in the pre-eclamptic patients (mean 4.48 ± 0.108 mmol/l) compared to control level (mean of 3.96 ± 0.059 mmol/l). Blood urea nitrogen in pre-eclampsia ranged between 1.2 and 21.9 mrnol /litre with a median of 5.05 mrnol/l while that for the controls ranged between 1.0 and 2.9 mmol/l with median value of 1.7 mmol/l. The corresponding clearances had a mean of 47.21 mls/min with SEM of 2.231 and 74.287 ml s/min with a SEM of 4.446 for the preeclampsia and controls respectively, (P <-001). Serum creatinine in the pre-eclamptic patients ranged from 60 to 206 micromolll with median value of 88 micromol/l and that of controls ranged between 50 and 127 micromol/l with a median value of 78 micromoi/i. p <- 001. Creatinine clearance for pre-eclamptics ranged between 40.5 and 133.8 mls/min and that of the controls between 67.0 and 164.6 mIs/min. The mean creatinine clearances for pre-eclamptic patients and controls were 82.521 mls/min with SEN of 2.461 and 104.03 mllmin with SEM of 3.69 respectively, P < 001.

Serum uric acid for pre-eclamptics ranged from 70. to 1500 micromol/L with mean of 768.67 micromol/L while that of the controls ranged from 51 to 598 with a mean of 243.43 micromol/L. The corresponding median uric acid clearances for pre-eclamptics was 4.081 ml/min and that of the controls was 9.313 ml/min, (P <- 001). Urine osmolality for the pre-eclamptic patients ranged from 100. to 840 mosmol/kg with a median of 330 mosmol/kg while that of controls ranged between 120 to 840 rnosrnl/kg with a median of 385 mosml/kg. There was no significant

difference noted between the two groups. Associations between blood pressure, parity, age and renal functions were investigated but there was no significant correlation in both cases and controls except for that of age and urea clearance which tended to show that the older the subject the better the urea clearance.' The study seemed to suggest that pre-eclampsia does impair the glomerular function of the kidney to an extent, however, no significant impairment as far as the concentration aspect of the kidney was concerned.