F220 Arch Dis Child Fetal Neonatal Ed 1998;78:F220–F221 Arch Dis Child Fetal Neonatal Ed: first published as 10.1136/fn.78.3.F220 on 1 May 1998. Downloaded from Hydrops fetalis due to ABO incompatibility

Maura McDonnell, Simon Hannam, SP Devane

Abstract along the 50th percentile. The second twin was Antenatal haemolysis in association with limp and bradycardic, requiring intubation and ABO incompatibility occurs very rarely. ventilation. On admission to the nursery he was Two cases of hydrops fetalis in black pale, jaundiced, and oedematous, with ab- infants caused by anti-B haemolysins are dominal distension and hepatosplenomegaly. reported. The greater severity of His birthweight was 2032 g. Initial investiga- ABO incompatibility in black African tions again showed features of haemolytic peoples may have important implications anaemia (table 1). A double volume exchange for screening in this ethnic transfusion was required. group. In both cases full infection and metabolic (Arch Dis Child Fetal Neonatal Ed 1998;78:F220–F221) screens were carried out and were normal. The jaundice and hepatosplenomegaly gradually Keywords: ABO incompatibility; hydrops fetalis; black resolved over a period of 8 weeks. Africans

Discussion ABO incompatibility is the most common There isa1in5chance of ABO incompatibil- materno-fetal blood group incompatibility ity between fetal red cells and maternal serum, which, unlike rhesus , is usually a yet ABO haemolytic disease of the newborn problem of the neonate rather than the . (HDN) is relatively uncommon, occurring in Anaemia is rare; the main clinical problem is about 2% of all births. Only three cases of jaundice. The incidence in the United hydrops fetalis with neonatal survival have Kingdom is about 2% of all births, but severe been described in association with ABO haemolytic disease occurs in only 0.03% of incompatibility.1–3 This condition is rare be- births. Hydrops fetalis in association with ABO cause anti-A and anti-B that de- incompatibility is extremely rare, with single velop during the first few months of life are case reports only. We report two cases of usually IgM immunoglobulins that cannot hydrops caused by ABO incompatibility. cross the placenta. HDN can only be caused by IgG (immune) maternal antibody. A high titre Case reports of immune antibody will not necessarily cause CASE 1 problems in utero as A and B antigens are A girl was born at term to a Nigerian couple. present on cells of all other tissues and body The mother’s blood group was O rhesus posi- fluids, and not only on red cells. These fetal

tive. An emergency caesarean section was per- antigens help to protect the incompatible fetal http://fn.bmj.com/ formed for fetal distress. At delivery the baby red cells by neutralising transferred maternal was cyanosed, limp, and bradycardic, requiring antibody. intubation and ventilation. Her birthweight The incidence of severe HDN varies among was 2740 g. She was pale and oedematous with racial groups. A higher incidence and severity a petechial rash over the trunk and had a has been observed among Latin American4 and distended abdomen with marked hepato- Black peoples.5 In a study of 509 Nigerian volun-

Department of Child splenomegaly. Initial investigations showed teers 53.6% of group O individuals had anti-A on September 28, 2021 by guest. Protected copyright. Health features of haemolytic anaemia (table 1). A haemolysins, 62.7% had anti-B haemolysins Kings College Hospital Denmark Hill double volume exchange transfusion was and 47.9% had both. Thus Nigerians have a London SE5 9RS performed at 2 hours of age. high level of anti-A and anti-B haemolysins M McDonnell compared with Europeans, and unlike Europe- S Hannam S P Devane CASE 2 ans, many group O individuals in Nigeria are This boy was the second of twins born at term “dangerous” rather than “safe” universal blood Correspondence to: to an Afro-Caribbean woman whose blood donors.6 Dr Simon Hannam. group was O positive. Her partner was The cases reported here show that severe Accepted 4 November 1997 Nigerian. During both twins grew haemolysis can occur as a result of ABO incompatibility and that this diagnosis should Table 1 Clinical data at presentation be considered in the antenatal evaluation of hydrops fetalis. It is not cost eVective to screen Case 1 Case 2 for ABO incompatibility as there is no test that Haemoglobin (g/l) 58 99 is of high predictive value for severe HDN. It is Platelet count (× 109/l) 47 110 Reticulocyte count (× 109/l) 160 272 known, however, that haemolysis can be more Initial / peak (µmol/l) 250 / 450 214 / 232 severe in certain racial groups and so there may Conjugated SBR 165 152 be a case for screening for immune antibodies AST (IU/l) 404 645 Blood group B postitive B positive in these groups to monitor that may be Direct Coomb’s test Positive Positive at risk. This may be combined with antenatal Maternal anti B titre 1:1280 1:1280 scanning to look for early signs of hydrops. Blood film Polychromasia Polychromasia Cord blood testing could then be considered in Hydrops fetalis due to ABO incompatibility F221 Arch Dis Child Fetal Neonatal Ed: first published as 10.1136/fn.78.3.F220 on 1 May 1998. Downloaded from

selected cases. This would be of particular 3 Stiller RJ, Herzlinger R, Siegel S, Whetham JCG. Fetal associated with ABO incompatibility: case report importance in areas with a high ethnic mix. and review of the literature. Am J Obstet Gynecol Finally, early neonatal discharge may be risky 1996;175:1371-2. for babies of group O women with high 4 Cariani L, Romano EL, Martinez N, Montano R, Suarez G, Ruiz I, Soyano A. ABO haemolytic disease of the newborn: antibody titre, or with a history of ABO incom- factors influencing its severity and incidence in Venezuela. patibility in a previous pregnancy. J Trop Pediatr 1995;41:14-21. 5 Vos GH, Adhikari M, Coovadia HM. A study of ABO incompatibility and in black South Afri- 1 Gilja BK, Shah VP. Hydrops fetalis due to ABO incompat- can newborn infants. Transfusion 1981;21:6:744-9. ibility. Clin Pediatr 1988;27:210-12. 6 Okafor LA, Enebe S. Anti-A and anti-B haemolysins, 2 Sherer DM, Abramowicz JS, Ryan RM, Sheils LA, dangerous universal blood donors and the risk of ABO Blumberg N, Woods JR. Severe fetal hydrops resulting antagonism in a Nigerian community. Trop Geogr Med from ABO incompatibility. Obstet Gynecol 1991;2:897-9. 1985;37:270-2. http://fn.bmj.com/ on September 28, 2021 by guest. Protected copyright.