If your blood type is RH negative, know that doctors usually advise women who have undergone a surgical abortion, miscarriage or childbirth to take an injection of Human Immunoglobulin-Anti-D. This needs to be done because if the embryo happens to have a RH + blood type that comes into contact with the RH negative blood type from the woman, she might develop antibodies in her blood that can affect the next baby born.
However, researches on medical abortion and miscarriage during the first trimester (first 12 weeks) have shown that there is little contact or no contact al all between the blood of the woman and the embryo’s and that the woman don’t produce enough antibodies that may affect the next embryo. (29)
For this reason we do not recommend an injection of Human Immunoglobulin-Anti-D. But if you feel insecure, you should get medical advice soon after making a medical abortion. Just say you had a miscarriage and that your blood type is RH-, the doctor can decide whether or not you should get an injection of Human Immunoglobulin-Anti-D.
The scientific evidence that the administration of Human Immunoglobulin-Anti-D for vaginal bleeding during the first trimester, prevents the sensitisation in women or the development of hemolytic disease (even Erythroblastosis Fetalis) in the newborn are minimal. The practice of administrating Human Immunoglobulin-Anti-D in women with spontaneous first-trimester abortions is based on expert opinion and extrapolation of the experience with maternal and fetal bleeding in advanced pregnancies. Its use for the first trimester bleeding is not an evidence-based fact. (29)