Rh protein is a protein on the surface of red blood cells.
85% of people have Rh(+) blood, 15% have Rh(-) blood.
If the blood of an Rh(-) person meets Rh(+) blood, antibodies to Rh(+) are formed in the Rh(-) blood.
In a marriage, if the woman’s blood is Rh(-) and her husband’s blood is Rh(+), there is Rh incompatibility between the spouses. In this case, there is a possibility that the Rh (-) mother may carry a Rh (+) baby. There are measures to be taken to prevent problems in these pregnancies and in other pregnancies the mother will have.
If the Rh(-) mother with an Rh(+) partner is pregnant and the baby and their blood mix in any way, if the baby is Rh(+) (since this is not known in the unborn baby, the baby of every Rh(-) pregnant woman with Rh incompatibility with the partner is considered as Rh(+)), the baby will have the possibility to form antibodies against the baby’s blood cells. 0.25 ml of the baby’s blood is sufficient to generate this response
After the mother develops antibodies, the antibodies can pass through the placenta into the baby’s blood and start to destroy the baby’s blood cells, leading to profound anemia and many subsequent problems and even death. If the mother has antibodies during childbirth or after a curettage, these risks are still present in the next pregnancy.
In couples with Rh incompatibility, the indirect coombs test in the mother’s blood should be among the tests requested before pregnancy. The indirect coombs test shows whether the mother has ever been exposed to Rh(+) blood and formed antibodies. This can happen at the end of a pregnancy that she did not realize and unknowingly had a miscarriage.
Mother with negative indirect coombs is ready for a new pregnancy
In cases of threatened miscarriage, amniocentesis, vaginal bleeding, abdominal trauma during pregnancy, the mother may be administered a protective blood incompatibility injection against the possibility of antibody formation in the mother due to the mixing of the mother and the baby’s blood. If none of these conditions occur, the indirect coombs test is repeated at 28 weeks and if it is negative, i.e. the mother is not affected, the mother is given a protective blood incompatibility injection. After birth, the baby’s blood group is checked. If the baby’s blood group is negative, there is no need for any treatment, but if it is positive, the mother will again receive a blood incompatibility injection within 72 hours to protect future pregnancies. Even after a woman with Rh(-) blood type has undergone a voluntary or involuntary curettage, if the father is Rh(+) or the father is unknown, regardless of the baby’s blood type, a protective injection must be administered within 72 hours.
If the mother was affected in a previous or current pregnancy and the blood antibody test (indirect coombs) is positive, pregnancy follow-up should be performed in a center where high-risk pregnancies are followed up. If signs of anemia are detected in the baby, preterm delivery can be planned without waiting for 37 weeks. Another option is to give blood to the baby through the umbilical cord. If the baby has mild anemia, or if there are no symptoms of anemia, the term can be waited.
Hibbard BM: Immunological problems and pregnancy.
in Principles of Obstetrics. Butterworthh
Co. London 1988; 304.
Quenan JT: Rh and other blood group immunizations. in Management of High-Risk Pregnancy.Medical Economics Compy Lancaster 1985; 505-520.