Ultrasound-guided Fetal Intravenous Transfusion for Severe Rhesus Haemolytic Disease

Abstract

Intraperitoneal transfusion of unborn infants with severe rhesus hemolytic disease gives poor results when the fetus is of low gestational age and has hydrops. Direct intravascular transfusion of fetuses under feto-scopic control at 23 to 26 weeks of gestation is more efficient, but it cannot be used beyond that age because of fetoscopic limitations. The authors have therefore tried direct intravenous transfusion of fetuses through the hepatic part of the umbilical vein using a thin needle guided by ultrasound. The procedures conformed with the Declaration of Helsinki of 1975. Results in two cases are described. Case 1, a 33-year-old woman (blood group O, rhesus-negative) was in her fifth pregnancy. Ultrasonic assessment showed a fetus of normal size for 29 weeks. Fetal ascites was present, and the amniotic fluid bilirubin concentration was 14 μmol/liter(0.8 mg/100 ml), which was in the “severely affected” zone of the prognostic chart. The patient was treated with betamethazone (12 mg daily for 2 days), ritodrine (10 mg four times daily), and phe-nobarbitone (100 mg daily). An intraperitoneal transfusion was planned, with 50 ml of group O, rhesus-negative (cde/cde) erythrocytes suspended in sterile isotonic sodium chloride (packed cell volume, 0.60 (60 per cent)). To prevent immunological complications, the cell suspension was irradiated with 2160 rad for 4 minutes before use. During the transfusion, the authors observed a dilated umbilical vein and gave a further 10 ml of blood into the hepatic part of the vein. A fetal blood sample, which looked like reddish serum, showed the fetus to be group A, rhesus-positive, and gave a strongly positive reaction to a direct Coombs test. A second intravenous transfusion of 25 ml was given a week later. A fetal blood sample before the second transfusion showed a ratio of fetal to adult erythrocytes of 37:63. At 32 weeks, a girl of 1 700 g was delivered by cesar-ean section. The Apgar score was 3 at 1 minute and 10 at 5 minutes. The umbilical cord hemoglobin concentration was 6.4 g/dl and the bilirubin concentration 144 μmol/liter (8.4 mg/100 ml). The ratio of fetal to adult erythrocytes was 22:78. The infant had a slight bluish discoloration around the umbilicus, possibly a slight he-matoma. During the next 2 days, five exchange transfusions were given because of high and rising serum bilirubin concentrations, the highest being 393 μmol/liter (22.9 mg/100 ml). There were no further complications. Case 2, a 25-year-old woman in the 23rd week of pregnancy, was admitted for termination of pregnancy after a prenatal diagnosis of genetic disease (chromosomal abnormality). There was no evidence of rhesus isoimmunization. Ultrasound-guided puncture for fetal blood sampling was performed. Biparietal diameter was compatible with the age of gestation. Puncture of the hepatic part of the umbilical vein was performed under epidural anesthesia. The tip of the needle was visualized on the oscilloscope in the lumen of the vein and 0.5 ml of blood was withdrawn. Analysis on a Coulter counter showed 100 per cent fetal blood. Subsequently, 40 mg of dinoprost trometamol (Amoglandin) were instilled into the amniotic cavity for termination. Knowledge of various factors—for example, the size of transfusion, the cardiovascular effects of transfusion, the importance of different blood variables in fetal blood—should be established, but it is hoped that direct intravenous fetal tranfusion will improve the prognosis of high risk, rhesus-sensitized fetuses that cannot be saved by traditional methods.