The effect of covert bacteriuria in schoolgirls on renal function at 18 years and during pregnancy.

Schoolgirls shown to have covert bacteriuria (CB) by a screening programme and followed up for 5 years to assess whether chemotherapy had any beneficial effect, underwent a further assessment of renal function at the age of 18 years and during subsequent pregnancies. At age 18, glomerular filtration rate (GFR) and urine concentrating ability were the same as in controls, but fractional reabsorption of glucose was significantly reduced in those who had previously been prescribed chemotherapy because of renal scarring or who had been randomly allocated not to receive prophylactic chemotherapy. Those who had had CB as schoolgirls had a higher frequency of CB in pregnancy than did controls, whether or not prophylactic chemotherapy had been given to the subjects when they were schoolgirls. Furthermore, compared with girls who had had such treatment, untreated patients had smaller increments in GFR, reduced fractional reabsorption of glucose, and more than usual degree of glycosuria during pregnancy. This suggests that subclinical renal damage may be prevented by prophylactic chemotherapy but this advantage is unmasked only by the physiological demands of pregnancy.