Prevalence of positive direct antiglobulin test and clinical outcomes in Surinamese newborns from D-negative women.

BACKGROUND: In low-resource countries, screening for D antibodies to detect pregnancies at risk for hemolytic disease of the newborn is not routine practice. Retrospective data showed that 5.5% of Surinamese newborns of D-negative women had a positive direct antiglobulin test (DAT), indicating the presence of maternal antibodies against fetal antigens. Here, the frequency and clinical relevance of DAT positivity is evaluated. STUDY DESIGN AND METHODS: Between April 2015 and June 2016, an observational, multicenter cohort study was undertaken among Surinamese newborns born to D-negative women. In newborns, the DAT was performed, and clinical outcomes between DAT-negative and DAT-positive newborns were compared. RESULTS: Of the 232 evaluable newborns, 19 (8.2%) had a positive DAT, of which 11 of 15 antibody-tested newborns had D antibodies. DAT-positive newborns had lower hemoglobin levels (p = 0.02) and a trend toward higher bilirubin concentrations (p = 0.09) in the first days of life compared with DAT-negative newborns. DAT-positive newborns were admitted more frequently (p = 0.02), needed phototherapy treatment almost four times as often as DAT-negative newborns (26% vs. 7%; p = 0.008), and therapy took 2 days longer (p = 0.01). Exchange transfusions were performed in two newborns with D antibodies, both complicated with sepsis. The hospital stay was 2.5 days longer for DAT-positive newborns (p = 0.007). Overall, the prevalence of hemolytic disease of the newborn requiring treatment was 2.2% among the whole cohort of newborns. CONCLUSION: We found a high prevalence of DAT positivity with substantial need for hyperbilirubinemia treatment in newborns in Suriname. These results stress the necessity for better management procedures in D-negative women.

D antibodies in pregnant women in multiethnic Suriname: the observational RheSuN study.

BACKGROUND: Maternal antibodies against the D antigen are the most common cause of severe hemolytic disease of the fetus and newborn (HDFN). In high-income countries, the risk of D immunization has been reduced by routine antenatal and postpartum administration of RhIG from 13% to less than 0.5%. In less-resourced countries, such as Suriname, red blood cell (RBC) antibody screening during pregnancy and prophylactic RhIG administration are not routine. Accurate data on D immunization risk is not available. In the RheSuN (Rhesus Surinamese Neonates) study, the prevalence and the hemolytic potential of maternal D antibodies were investigated. STUDY DESIGN AND METHODS: A multicenter cross-sectional study in four major hospitals in Paramaribo, Suriname, covering 90% of approximately 10,000 births yearly in Suriname. Included were D- pregnant women of various ethnicities seeking routine prenatal care and/or their newborns. RESULTS: D antibodies were detected in 19 of 214 D- pregnancies (8.9%; 95% confidence interval, 5.1%-12.7%), in 2.0% of primigravid and 11.7% of multigravid women. The direct antiglobulin test was positive in 11 of 13 tested D+ newborns. Determination of D antibody titers and antibody-dependent cell mediated cytotoxicity (ADCC) assay revealed three newborns at high risk for HDFN (ADCC > 50%). CONCLUSION: D immunization risk in Suriname women is comparable to the pre-anti-D prophylaxis era in high-income countries. Recommended is free-of-charge routine RBC antibody screening and prophylactic RhIG administration for women at risk for D antibody formation as part of standard of ante- and postnatal care.