High-risk Pregnant Women Post-experimental Evaluation Of Evidence-based Study Of Fetal HDN

Hemolytic disease of the newborn (HDN) can be seen in incompatible pregnancies. The IgG antibodies in the maternal circulation cross the placenta, cause hemolysis in the fetus. The disease often happens to fetus and the newborn, may lead to abortion. The slight representations are anemia, edema and hepatomegaly; the serious is uterine dead. To the newborn it may cause kernicterus, with the sequela of sport impediment, amentia, etc. This will bring a great pressure to the family and society. Now we have known that there are 26 blood systems and more than 400 blood antigens. Though many blood systems can cause HDN, the most popular are ABO and RhD. In our country, only 0.24% of the Han people is RhD(-),and nearly 5% in the minority, these numbers are lesser than those 15% of the Caucasian, so most of the HDN is caused by ABO system. Most of the ABO incompatible pregnancy can be seen in mother of blood type O, and the fetus is A or B, it can happen in the first labour. The normal clinical test to predict whether it is HDN is Indirect antiglobulin test (IAT). This method can be used to test the weak antibody of the early pregnancy, it has high sensitivity, but the test must be done in the standard condition, and the correlation between titer of alloantibodies and HDN is still deficiency. The objective of this research is to explore relationship between serum anti-A(B) IgG subclasses of pregnant women with ABO blood group incompatibility and HDN, on the basis of knowing the titer of alloantibodies and whether the newborn is HDN. We hope that our results can make up the deficiency of IAT to predict HDN, and bring a more effective method to predict ABO-HDN. To explore the relationship between the valence of antibody of pregnant woman in serum and Hemolytic Disease of Newborn(HDN).Method:We collected The samples from 3947 couples before delivery were collected for the identification of ABO and Rh(D) blood type. They are from the samples of Dalian Red cross blood center, during Oct.2003 and Aug 2008. The age of the mothers are between 21 and 42, the weeks of gestation are between 20 and 38 weeks. They are in good health, without innutrition, abnormal pregnancy and other problems. And the samples of the newborn are sent to test within 48 hours after its birth. Measure the valence of serum anti-A/B IgG by microcolumn gelatum with mismatched ABO and RhD blood type.Result:The mismatched ABO were 2371 couples with the husband and the pregnant wife, There were 1287 cases'valence of antibodies were higher than 1:64.There were 980 cases(97.3%)of O blood type and 15 cases(1.3%) of A and 17 cases(1.4%) of B. The mismatched Rh were 30 couples.In which 3 cases valence of anti-D were higher than 1:256.Conclsion HDN major occurrence in the fetus and the newborn with type A or B or AB and its mother with type O.According to IAT we got the titer of anti-A (B) IgG, and found that 1287 of 2371 are higher than 64 or equal to 64, the other 4 are lower than 64. And 384 of the 517 are HDN positive,133 of the 517 are HDN negative; 1 of the 4 is HDN positive,3 of the 4 are HDN negative. There are 19 women whose titer is higher than 256 or equal to 256,12 of the 19 are HDN positive,7 of the 19 are HDN negative. The anti-A or B IgG subclasses were isolated by absorption/elution from the sera of alloimmunized pregnant womenχ2= 1420.440, v= 2, P= 0.000, difference among the three groups was significant, it could be different pregnant sub-pregnant women (with fetal blood group incompatibility) of pregnancy, fetal risk of neonatal hemolytic disease were significantly different, based on average rank time, further concluded that pregnant women with more pregnancies, had a different blood type fetal greater risk of hemolytic disease of newborn. Maternal age and pregnancy history and the occurrence of HDN have great relationships with the maternal age increases, the wife blood group incompatibility of maternal serum in the IgG antibody titer increased, and the increased probability of occurrence HDN. The results suggest that older pregnant women and pregnant women had a history of abortion must be the immunological detection of its own antibody titer, especially the latter, HDN will occur after two births, pregnancy 2 times a pregnant woman must pay attention to. We use IAT to test the titer of the elution, and find that the titer is nearly the same as the titer of the serum. The result of IAT showed that the correlation between antibody levels and HDN was not absolutely, we could not judge the severity of HDN only by measuring antibody levels. Disease severity is influenced by factors in addition to antibody concentration, these factors remain to be fully elucidated but may include the subclass and glycosylation of maternal antibodies, the structure, site density, maturational development and tissue distribution of blood group antigens, the efficiency of IgG transport to the fetus, the functional maturity of the fetal spleen, polymorphisms which affect Fc receptor function, and the presence of HLA-related inhibitory antibodies. Applied blood group serology to detect his wife, pregnant women, IgG antibody screening and antibody titer determination method is simple, easy to promote the use of, and timely post-neonatal bilirubin monitoring, forecasting is still HDN prenatal and post-natal treatment programs to determine more practical method. And can guide clinical to take effective preventive and treatment measures.