A Review of 33 Liquor Amnii Analyses during Pregnancy Complicated by Rhesus Incompatibility

In rhesus-negative women who have had previous babies severely affected by rhesus incompatibility, the maternal rhesus antibody titre during a subsequent pregnancy offers only a poor indication of the degree to which the developing foetus will be affected. This has induced workers to look for laboratory tests that can give more reliable information. In an attempt to detect excessive haemolysis in the foetus, Walker (1957) made spectrophotometry measurements of the liquor amnii, and found that the amount of yellow pigment that it contained corresponded closely with the degree of anaemia of the baby, as measured by the haemoglobin content of cord blood.