PREDICTION OF OUTCOME IN ABO INCOMPATIBLE NEONATES WITH RESPECT TO MATERNAL IgG ANTI-A AND ANTI-B TITRE IN O GROUP MOTHERS Govt T.D Medical College, Alappuzha Dr Shahida, Dr Meena D, Dr Sasikala N, Dr Mayadevi S

BACKGROUND The fetus may inherit father’s blood group whose antigen on red cells has corresponding antibodies in the mother resulting in maternal-fetal blood group incompatibility. As the incidence of Rh D alloimmunization has decreased after the introduction of anti-D prophylaxis, ABO-incompatibility is now the major cause of immune hemolytic disease of the newborn Problems encountered from ABO maternal antibodies to the corresponding A or B antigens on the fetal red cells stimulated this study

AIM To evaluate predictors for risk of hyperbilirubinaemia in ABO- incompatible neonates with emphasize on maternal IgG anti-A ⁄ B titres To assess if maternal antibodies were associated with increased duration of phototherapy or repeated invasive treatment with IVIG or EXT

METHODS OF STUDY Cross sectional study, for a period of one and half years Inclusion criteria - O group mothers who had good obstetric history - Maternal antibody screen negative for other blood group systems - A and B group babies with same Rh-D status as that of mother with no predisposition to other causes of hyperbilirubinemia Consent when admitted for labor/immediate postnatal period 627 healthy Blood group O women recruited/ 200 with A or B infants . Baby’s sample- ABO and Rh typing, DAT Maternal sample- ABO and Rh typing, - IgG anti-A/B titre estimation by tube technique (with DTT)

DEMOGRAPHIC CHARACTERISTICS OF 200 NEWBORNS WITH ABO INCOMPATIBILITY Total (n=200) Gestational Age Preterm(36wks) Term (37-40wks) Post term (>40wks)   7 192 1 Birth weight 2–2.49 kg 2.5-3.9 kg ≥4 kg 17 180 3 Gender Male Female 115 85 Blood group A B Parity Primigravida Multigravida 99 101 89 111 DEMOGRAPHIC CHARACTERISTICS OF 200 NEWBORNS WITH ABO INCOMPATIBILITY Gender and birth weight had no relation with clinical outcome ABO incompatibility was observed in 31.8% of pregnancies with almost equal O–A (99) and O–B (101) frequencies Number of affected newborns were higher in primigravidae (39/93)

CLINICAL CHARACTERISTICS OF 200 NEWBORNS WITH ABO INCOMPATIBILITY Total Number Significant hyperbilirub- inaemia Yes No 93 (46.5%) 107 Initial Hb ≥17 (no anemia) 17- 12 (mild-mod) ≤12 (severe) 115 (57.5%) 81 4 Evidence of hemolysis Present Absent 21 (10.5%) 179 Reticulocyte count ≥6.5% <6.5% 17 183 DAT Positive Negative 23 (11.5%) 177 46.5% had significant hyperbilirubinemia and required phototherapy of which 59% (55/93) belonged to O-A group Jaundice- detected within the first 24 hours in 25.5% Remaining 40  hyperbilirubinemia in subsequent days Most of the newborns had their peak level of bilirubin in the 2nd or the 3rd day History of neonatal jaundice in siblings, positive DAT & high maternal antibody titre had significant association with higher chance of elevated bilirubin levels (p<0.05)

CLINICAL CHARACTERISTICS OF 200 NEWBORNS WITH ABO INCOMPATIBILITY… Total Number Significant hyperbilirub- inaemia Yes No 93 (46.5%) 107 Initial Hb ≥17 (no anemia) 17- 12 (mild-mod) ≤12 (severe) 115 (57.5%) 81 4 Evidence of hemolysis Present Absent 21 (10.5%) 179 Reticulocyte count ≥6.5% <6.5% 17 183 DAT Positive Negative 23 (11.5%) 177 In infants with ABO HDFN, high maternal antibody titre high bilirubin levels DAT positivity significantly associated with higher risk for the development of anemia. The proportion of ABO HDFN was found to be 3.6% (23/627)

CLINICAL CHARACTERISTICS OF 200 ABO INCOMPATIBLE NEWBORNS BASED ON DAT STATUS DAT Negative (n=177) DAT Positive (n=23) P value Blood group - A B 82 95 17 6   0.011 Mean G.A 38.15 38.04 NS Mean Birth weight 2.98 2.95 Mean of First measured bilirubin 3.56 8.24 <0.05 Mean Peak bilirubin 11.07 15.18 Ab titre ≥128 26 20 Phototherapy 71 23 IVIG 3 8 EXT 2 0.013 NNTX 1 Positive DAT was significantly associated with increased risk of high bilirubin levels, anemia and high maternal Ab titre in ABO HDFN and it had positive correlation with intensity of treatment.

TREATMENT MODALITIES IN THE 200 INFANTS WITH ABO INCOMPATIBILITY Majority of the affected neonates (80/93) improved with phototherapy alone 10 cases received IVIG when (one of them required a second dose of IVIG) so that exchange transfusion could be avoided Phototherapy + IVIG + exchange transfusion in 2 infants - referred cases with severe hyperbilirubinemia on presentation

ANTIBODY TITRE IN THE MOTHER OF ABO INCOMPATIBLE NEWBORNS 23% of mothers had antibody titre ≥128 2 severely affected infants with ABO HDFN had Ab titre of 512 Maternal Ab in ABO HDFN positively correlated with bilirubin levels, DAT positivity and intensity of treatment & was negatively correlated with initial hemoglobin levels

MATERNAL IgG ANTIBODY TITRE LEVELS IN RELATION TO DAT, EVIDENCE OF HEMOLYSIS AND MODE OF TREATMENT AMONG ABO INCOMPATIBLE NEONATES Ab Titre N Hemolysis DAT Phototherapy IVIG EXT NNTX 8 12 16 37 4 32 57 15 64 48 3 31 1 128 25 5 22 256 11 13 512 2 Total 200 21 23 93 10 P value   <0.05 Out of the 10 neonates received treatment with IVIG, 7 (70%) were DAT positive and 80% had titre ≥256. Positive DAT & maternal antibody titre ≥256 had significant association with intensity of treatment & ICU stay.

COMPARISON OF MEAN VALUES BETWEEN O-A AND O-B INFANTS WITH SIGNIFICANT HYPERBILIRUBINEMIA (THE AFFECTED NEWBORNS) Parameters Mean   P value Significance Blood group A (n= 55) Blood group B (n=38) Birth weight 2.93 2.88 0.507 NS First bilirubin 5.88 5.48 0.441 Peak bilirubin 14.16 13.40 0.185 Initial Hb 16.29 16.58 0.505 Reticulocyte count 4.44 4.16 0.725 Duration of hospital stay 3.39 0.995 In affected neonates, no significant difference in levels of bilirubin, Hb, DAT, signs of hemolysis and intensity of treatment between the O-A and O-B groups though most affected neonates belonged to blood group A.

CONCLUSION ABO incompatibility was observed in 31.8% of pregnancies with almost equal O–A (99) and O–B (101) frequencies. Majority of ABO incompatible newborns were unaffected. Infants with history of neonatal jaundice in siblings had significantly higher bilirubin levels. Maternal IgG anti-A ⁄-B titres contribute to the prediction of risk of severe hyperbilirubinaemia in ABO-incompatible neonates, in addition to blood- grouping and DAT testing.

Reference Polayesh SH and Mcnally J, Jr. Isoimmunisation with A and B factors and its relation to hemolytic disease of the newborn. Amer. J. Elin. Path. 1948; 18: 375. D. Voak, C.C.Bowley. A detailed serological study on the prediction and diagnosis of ABO hemolytic disease of newborn (ABO HD). Vox Sanguinis. Nov 1969; 17, 5: 321-348. Sajith V, Meena D and K.C Usha. Frequency of antibodies in haemolytic disease of foetus and newborn. Jemds.com. Orzalesi M, Gloria F, Lucarelli P, Bottini E. ABO system incompatibility: relationship between direct Coombs’ test positivity and neonatal jaundice. Pediatrics 1973; 51: 288–9. Kumari K.C. Usha, P.V.Sulochana. Detection of high risk pregnancies with reaction of ABO Hemolytic disease of newborn. Indian J of Peaditrics.1998;61-62 Schonitzer D, Frisch H. Incidence, laboratory diagnosis and serologic prediction of hemolytic disease of newborn infants due to ABO incompatibility. Padiatr Padol. 1984; 19(3): 263-78. Y R Bhat & C G Pavan Kumar (2012) Morbidity of ABO haemolytic disease in the newborn, Paediatrics and International Child Health, 32: 2, 93-96. Egil Bakkeheim. Maternal IgG anti-A and anti-B titres predict outcome in ABO-incompatibility in the neonate. July 2009. Acta Pædiatrica ISSN 0803–5253

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