Abstract
Amniotic fluid total protein content was measured in 129 samples from 112 normal pregnancies and 223 samples from 118 pregnancies complicated by Rhisoimmunization. A few samples were also obtained from pregnancies with other complications. A biuret method was used. The results showed that the total protein content is elevated in cases of mild and of very serious fetal disease. Intermediate stages of isoimmunization were associated with comparatively low protein levels. This may indicate that a high protein level may have a protective influence against the effects of isoimmunization. Because of the inability to discriminate between mild and very serious cases of isoimmunization protein estimations will be of limited value in the practical management of isoimmunized pregnancies. Due to the progressive decrease in total protein concentrations after the 24th week in normal pregnancies protein estimations may be of some value in determining fetal age.