“…However, large-scale studies on pregnant women need to be done in order to collect sufficient evidence to formulate guidelines and to define indications for alloantibody screening and identification. 11 Alvey JP in their study on Rh Incompatibility, which was an investigation in 200 cases, found that spectrophotometric analysis of a single specimen of liquor amnii, preferably taken at 32 weeks, affords a means of accurately determining the extent of the hemolytic process, especially when regard is given to both the type of curve produced and to a quantitative assessment of bilirubin in the liquor. By this method, it is possible to segregate all cases of Rh isoimmunization into three groups, designated A, B, and C. It is suggested that induction of labor is unnecessary in Group A (26.5 per cent of cases), that induction of labor at 38 weeks suffices in Group B (41 per cent of cases), and that, between 34 and 36 weeks, it is indicated in Group C (32.5 per cent of cases).5.…”