Rh incompatibility produces a wide variety of outcomes. Sometimes only mild anemia, and perhaps a little jaundice, are the only signs there has been a conflict. But sometimes the results are catastrophic. The first pregnancy is rarely a problem because blood is often not exchanged until the time of birth. But with each subsequent pregnancy, the risk for hydrops increases.
Hydropic babies are bloated, swollen, and pale.
Enlarged hearts, livers and spleens are unable to perform their vital duties. The swollen lungs can make breathing impossible. Many die shortly after birth. Many hydropic babies are stillborn. In 1963 an event occurred that began to change the story.