Daniels Geoff, Finning Kirstin, Martin Pete, Massey Edwin
International Blood Group Reference Laboratory, Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK.
Prenat Diagn. 2009 Feb;29(2):101-7. doi: 10.1002/pd.2172.
Fetuses of women with alloantibodies to RhD (D) are at risk from hemolytic disease of the fetus and newborn, but only if the fetal red cells are D-positive. In such pregnancies, it is beneficial to determine fetal D type, as this will affect the management of the pregnancy. It is possible to predict, with a high level of accuracy, fetal blood group phenotypes from genotyping tests on fetal DNA. The best source is the small quantity of fetal DNA in the blood of pregnant women, as this avoids the requirement for invasive procedures of amniocentesis or chorionic villus sampling (CVS). Many laboratories worldwide now provide noninvasive fetal D genotyping as a routine service for alloimmunized women, and some also test for c, E, C and K.In many countries, anti-D immunoglobulin injections are offered to D-negative pregnant women, to reduce the chances of prenatal immunization, even though up to 40% of these women will have a D-negative fetus. High-throughput, noninvasive fetal D genotyping technologies are being developed so that unnecessary treatment of pregnant women can be avoided. Trials suggest that fetal D typing of all D-negative pregnant women is feasible and should become common practice in the near future.
具有抗D（RhD）同种抗体的女性所怀胎儿有患胎儿及新生儿溶血病的风险，但前提是胎儿红细胞为D阳性。在这类妊娠中，确定胎儿D血型是有益的，因为这会影响妊娠的管理。通过对胎儿DNA进行基因分型检测，可以高度准确地预测胎儿血型表型。最佳来源是孕妇血液中的少量胎儿DNA，因为这样可避免进行羊膜穿刺术或绒毛取样（CVS）等侵入性操作。现在全球许多实验室都为同种免疫的女性提供无创胎儿D基因分型作为常规服务，有些实验室还检测c、E、C和K。在许多国家，会给D阴性孕妇注射抗D免疫球蛋白，以降低产前免疫的几率，尽管这些女性中高达40%会怀有D阴性胎儿。正在开发高通量无创胎儿D基因分型技术，以便避免对孕妇进行不必要的治疗。试验表明，对所有D阴性孕妇进行胎儿D分型是可行的，并且在不久的将来应成为常规做法。
