Complement in Hemolytic Disease of the Newborn

1. The 50 per cent complement levels in thirty-three normal newborn infants and twenty-three infants with D (Rh₀)-hemolytic disease were determined.

2. No statistically significant difference in complement values was found between the two groups.

3. In vitro tests with ten anti-D (Rh₀) sera demonstrated that there was no fixation of human complement.