Intra-amniotic urea as a midtrimester abortifacient: clinical results and serum and urinary changes

Seventy-four patients, from 16 to 20 weeks pregnant, received intra-amniotic urea (80 Gm.) and intravenous oxytocin for the purpose of inducing abortion. Seventy-one of the 74 patients were successfully aborted by the primary method with a mean injection-to-abortion interval of 18.33 hours. There were no serious side effects, and the mean hospital stay was 32 hours. Following urea injection, the mean serum urea nitrogen rose to 33 mg. per cent at 4 hours. Maximum changes in serum electrolytes occurred at 8 to 12 hours after injection and included a decrease in the mean concentrations of sodium, chloride, and carbon dioxide and an increase in serum potassium. An increase in the urinary excretion of urea began within 4 hours, but significant diuresis did not occur in the presence of intravenous oxytocin administration. There was a significant increase in the leukocyte concentration while hematocrit values remained unchanged. Beginning approximately 8 hours following urea injection, the mean plasma fibinogen concentrations decreased by approximately 15 per cent and the mean platelet count showed a drop of approximately 18 per cent. Fibrinogen-fibrin degradation products were significantly increased in 36 per cent of the patients studied.