Protein content of liquor amnii in prediction of severity of haemolytic disease of newborn.

Two series of cases of Rh isoimmunization were subjected to liquor examination for bilirubin and protein level. Series 1 comprised 298 cases for the years 1962 and 1963. Series 2 comprised 179 consecutive cases for 1967 in which preliminary selection for liquor examination had been made on the basis of previous history and maternal antibody titre.Bilirubin was measured as the liquor bilirubin ratio, and protein levels were estimated in series 1 by the Folin and Ciocalteau technique and in series 2 by a modified biuret method.Correlations with severity of haemolytic disease in the foetus was made, taking into account the stage of gestation of liquor examination. Both bilirubin and protein levels correlate with severity, but bilirubin is superior to protein. Interrelation of these measurements as bilirubin/protein ratio was inferior to bilirubin level as a method of forecasting severity.