The risk of Rh isoimmunization in ruptured tubal pregnancy.

In 9 (24%) out of 38 African women who had suffered a ruptured tubal pregnancy significant numbers of fetal erythrocytes (5 or more per 150,000 maternal cells) were found in the maternal circulation. This is a higher incidence than occurs after abortion and indicates that rupture of a tubal pregnancy is a potential source of Rh isoimmunization. The finding of fetal cells in the peritoneal cavity suggests that this is the main source of the fetal blood found in the maternal circulation. At operation on Rh-negative patients with ruptured tubal pregnancies, therefore, complete removal of the peritoneal blood should be attempted and the blood recovered should never be transfused into the patient, who should always receive prophylactic Rh immunoglobulin.