Fetal Rh factor determination

Causes of Rh incompatibility

There are five antigens in the Rh system. The most immunogenic of these is antigen D; its presence on the surface of red blood cells determines a positive Rh factor (Rh+). The proportion of Rh-positive individuals carrying the D antigen in the population is approximately 86%, while Rh-negative individuals (Rh-) without the D antigen constitute around 14%.

The course of pregnancy with an Rh-positive (Rh+) fetus in Rh-negative (Rh-) women is often complicated by hemolytic disease of the fetus associated with transplacental transfer of fetal erythrocytes into the mother's bloodstream. 98% of hemolytic disease cases in newborns are associated with the rhesus D antigen. Upon entering the bloodstream of an Rh- mother, it causes the formation of specific antibodies that penetrate the placenta, destroy fetal erythrocytes, subsequently leading to the development of hemolytic disease of the newborn.

Early manifestations of Rh incompatibility can be the cause of premature labor or spontaneous abortion. With each subsequent pregnancy with a Rh+ fetus maternal sensitization to the D antigen increases together with the risk of developing Rh incompatibility, regardless of whether the pregnancy is terminated or the delivery takes place.

PCR test

“Fetal RHD Genotyping” real-time PCR reagent kit produced by DNA Technology allows to determine the Rh status of the fetus in Rh-negative patients during early pregnancy to facilitate assessment of the Rh incompatibility risk and initiation of preventive measures. It can also be used in prenatal screening of pregnancy complications in Rh-negative women.