Relation between antibody titer in pregnant women with maternal-fetal ABO blood incompatibility and hemolytic disease of fetuses and newborns

Abstract

Objective To investigate the relationship between IgG antibody titer in pregnant women with maternal-fetal ABO blood incompatibility and hemolytic disease of fetuses and newborns.Methods From January 31 2009 to January 31 2010,1269 singleton pregnant women who were suspected to have maternal fetal ABO blood incompatibility in Department of Obstetrics and Gynecology,Southwest Hospital,Third Military University were collected.Anti-A or anti-B IgG titers of them were detected at 28-30 gestational age,and umbilical cord blood were taken when delivery and hemolytic disease of the newborn serological test were done to diagnose hemolytic disease of the newborn (HDN).The relationship between the titers and incidence of fetal or neonatal hemolytic disease was retrospectively analyzed by Kendall tau rank correlation.Results No IgG of anti-A or anti-B in serum were found in 58.4％ (741/1269) pregnant women,while the antibody titer of 5.1％ (65/1269) pregnant women were more than or equal to 1 ∶ 128.When they were tested again at 36 gestational week,the titer of 17 cases increased twice but lower than 1 ∶ 512.No signs of intrauterine hemolysis,such as edema,ascites and pleural effusion,were found.Three hundred and eighty neonates (29.9％,380/1269) were diagnosed as HDN.Among which,12 cases (3.2％,12/380) showed mild anemia and (or) jaundice within 24 hours after delivery.There was positive correlation between incidence of neonatal hemolysis and antibody titer(Tb=-0.293,P＜0.01).The incidence of HDN increased from 85.4％ (35/41) in women with antibody titer of 1 ∶ 128 to 5/5 inwomen with antibody titer at 1 ∶ 512 (x2=108.906,P＜0.01).Among 380 HDN neonates,322 cases were transferred to neonatal intensive care unit for phototherapy based comprehensive therapy,and two underwent exchange transfusion.All patients were cured.Conclusions The intrauterine hemolysis incidence of patients with suspected maternal-fetal ABO blood incompatibility is very low,and no special care is required during pregnancy.Anti-A or anti-B tests during pregnancy is helpful in early diagnosis and management of HDN. Key words: Maternal-fetal ABO blood incompatibility; Intrauterine fetus hemolysis; Neonatal hemolysis ; Treatment outcomes