Is antibody screening in Rh (D)-positive pregnant women necessary?

Abstract

Objective: Hemolytic disease of the fetus and of the newborn can be caused by incompatibility of maternal and fetal erythrocytes for Rh (D) or other blood type antigens. Routine antibody screening is advocated in all pregnant women, irrespective of whether they are Rh (D)-positive or Rh (D)-negative, to look for clinically significant alloantibodies other than Rh (D) that might cause hemolytic disease of the newborn. The purpose of this study was to assess the incidence of blood type antibodies other than Rh (D) in pregnant women attending for prenatal care in a typical urban population.Methods: A retrospective analysis was undertaken of the charts of all pregnant women followed throughout their entire pregnancy at our Women's Health Center from 1 January 1999 to 30 April 2002.Results: There were 1265 pregnant women included in the study: 465 had blood type A (36.7%), 269 type B (21.3%), 424 type O (33.5%) and 107 type AB (8.5%). A total of 1156 were Rh(D)-positive (91.4%) and 109 were Rh(D)-negative (8.6%). Of the Rh(D)-positive women, 522 (41.3%) underwent routine antibody screening in the first trimester. Only one woman (0.2%) had a positive antibody screen. Of the 109 Rh (D)-negative women, one (0.9%) had a positive third trimester screen witha negative first trimester screen.Conclusion: Routine antibody screening of Rh (D)-positive women is probably not warranted from a clinical cost-benefit perspective.