Clinical significance of the detection of Rh blood group antigens and irregular antibodies in pregnant women with a second pregnancy

Objective:To investigate the phenotype distribution of five antigens of Rh blood group system and the specificity of Rh blood group irregular antibodies in pregnant women with second child.To analyze the relationship between Rh blood group antibody and hemolytic disease of the newborn(HDN)in second-child pregnant women,and to provide laboratory basis for the diagnosis and treatment of hemolytic disease of the newborn(Rh-HDN).Methods:500 pregnant women with second child were collected as the study group and 500 pregnant women with first pregnancy as the control group(all pregnant women underwent obstetric examination in the integrated obsteric clinic of our hospital from January 2020 to January 2021).To detectethe Rh blood group antigens(D,C,c,E,e)of the two groups of samples,screene the irregular antibodies,identify the specificity of irregular antibodies,determine the titer and record the hemolytic disease of the newborn of pregnant women with positive Rh blood group antibodies.Results:There were 11 Rh phenotypes in the pregnant women with second child in the study group:CCDee(152cases,30.4%),CcDEe(136cases,27.2%)CcDee(84cases,16.8%),ccDEE(30cases,6%),ccDee(31cases,6.2%),CCDEe(14cases,2.8%),ccDEe(9cases,1.8%),cc dee(18cases,3.6%),CCDEE(2cases,0.4%),CcdEe(12cases,2.4%),Ccdee(6cases,1.2%),CCd ee(6cases,1.2%).A total of 42 cases(8.4%)in the pregnant women with second child were negative for RhD.There were 10 Rh phenotypes in the pregnant women with first pregnancy in the control group:CCDee(144cases,28.8%),CcDEe(138cases,27.6%),CcDee(90cases,18%),ccDEE(42cases,8.4%),ccDee(28cases,5.6%),CCDEe(10cases,2%),ccDEe(8cases,1.6%),cc dee(19cases,3.8%),CCDEE(1cases,0.2%),CcdEe(11cases,2.2%),Ccdee(9cases,1.8%).A total of 39 cases(7.8%)in the pregnant women with first pregnancy were negative for RhD.In the pregnant women with second child in the study group,the positive rate of irregular antibody screening was 4.0%(20/500),and the specificity of Rh blood group antibodies was found as follows:anti-E 1.8%(9/500),anti-D 1.4%(7/500),anti-C 0.4%(2/500)and anti-Ec 0.4%(2/500).The positive rate of irregular antibody screening in the pregnant women with first pregnancy in the control group was 0,and the difference between the two groups was statistically significant(P<0.05).Rh-HDN was found in 10 newborns(2%)of the 20 women with positive irregular antibodies in the pregnant women with second child,and the antibody titer during pregnancy was more than 32.No Rh-HDN occurred in newborns in the pregnant women with first pregnancy,and the difference between the two groups was statistically significant(P<0.05).Conclusion:Pregnancy stimulation can increase the probability of irregular antibodies in pregnant women,and irregular antibodies in Rh blood group can easily cause Rh-HDN,so attention should be paid to routine detection of five antigens of Rh blood group and irregular antibody screening during prenatal examination.It is helpful for the early detection of Rh-blood irregular antibodies and the assessment of fetal or neonatal risk of Rh-HDN.

Kell Blood Group Maternal-Fetal Incompatibility in Lubumbashi （D. R. Congo）, Case Report

Introduction： The anti Kell is a major cause of hemolytic disease of the newborn; the third cause after ABO and Rhesus in frequency; and the second in terms of severity after rhesus type incompatibility. In Africa, 60% of the population is Kell negative. In Congo, Kell blood group determination is not systematically performed and almost non-existent in perinatology. We aimed to report a case of this immunization in routine practice. Method： This study is a clinical report of Kell immunization. Physical examination was performed and blood group determined. Clinical and biological follow up of the case： a review of the literature of Kell immtmizations is included. Result： A female newborn on day 4 of life with weight of 3,250 g born at term admitted to Sendwe＇s Hospital emergency for pallor and respiratory distress. History reveals jaundice at birth. The mother is P1G4A3D0, blood group Orh＋. Clinically the child is pale, jaundiced, present tachycardia, hepatomegaly, polypnea Brh＋. The diagnostic orientation is a maternal-fetal incompatibility. The realization of blood grouping Kell, Duffy and irregular antibodies research Kell type confirms the diagnosis of Kell hemolytic disease of the newborn. We discharged him after 14 days. Conclusions： The Kell type IFME is a purveyor of grave hemolytic disease of the newborn. His knowledge, prevention and proper care by a multidisciplinary team can prevent dramatic situations.