Changes in the management of severely Rh-immunized patients

Outcome for children treated with fetal intravascular transfusions because of severe blood group antagonism

OBJECTIVE

To describe the outcome for 92 fetuses treated between May 1987 and January of 1993 with intrauterine (intravascular) transfusions for severe hemolytic disease in comparison with a high-risk and a healthy control group.

STUDY DESIGN

Information on the perinatal period was obtained from the patient records. The children regularly attended the outpatient clinic, and a general pediatric examination was performed on each visit. The psychometer development of the child until age 4 1/2 years was assessed according to Gesell. At the age of 5 years, the adaptation part of the Denver Developmental Screening Test and a Dutch-language test were used. A neurologic examination was performed according to Touwen.

RESULTS

In our study, 77 (83.7%) of 92 fetuses were born alive after intravascular transfusions. The overall survival rate was 79.3%. The follow-up group included 69 infants, with an age range of 6 months to 6 years. Correlation between antenatal and perinatal features showed a significant negative relationship between the number of intrauterine transfusions and the duration of phototherapy (p = 0.002). The probability that neurologic abnormalities would occur was significantly greater when perinatal asphyxia had been present (p < 0.05) and with a lower cord hemoglobin level at birth (p = 0.03). The total number of children with disabilities was 10.1% (7/69).

CONCLUSIONS

The neurodevelopmental outcome for the group of survivors compared favorably with a group of high-risk, very low birth weight infants (10.1% to 18%), and less favorably with a healthy control group (10.1% to 6%).

Antenatal diagnosis of pediatric surgical anomalies. Counseling the family

Improvements in screening and diagnostic techniques now mean that hundreds of congenital anomalies can be antenatally diagnosed. It is, however, impossible and inappropriate to submit all pregnant women to a barrage of investigations. Screening is necessary before specific invasive investigations are initiated. These include history, physical examination, MS-AFP screening, estriol and hCG screening, and a Level II ultrasonography scan. Once at-risk pregnancies have been identified, a multidisciplinary team approach is commenced and further studies including Level II ultrasonography, amniocentesis, chorionic villus sampling, or cordocentesis can be performed so that an accurate diagnosis is available. Counseling of the parents throughout is essential so that appropriate decisions regarding this and further pregnancies can be made.

Alloimmune conditions and pregnancy

Transfer of fetal red blood cells and platelets to the maternal circulation can stimulate an immune response with production of immunoglobulin that can cross the placenta. Similarly, passage of maternal stem cells to an immunologically incompetent fetus can theoretically produce graft-versus-host disease. disease. Maternal sensitization to red blood cell antigens such as D and Kell can result in anaemia, hydrops, and death in an incompatible fetus. Current assessment of these pregnancies involves serial analysis of amniotic fluid bilirubin concentration, with umbilical cord blood sampling reserved for special circumstances; neither ultrasound or Doppler blood flow analysis are accurate in the prediction of fetal haematocrit. Intravascular transfusion is the treatment of choice for hydropic fetuses. Perinatal survival in non-hydropic fetuses is similar with either intravascular or intraperitoneal transfusion, and the choice of procedures is individualized. Isoimmune fetal thrombocytopenia is usually the result of maternal sensitization to the PlA1 antigen. There is significant risk of intracranial haemorrhage, both antepartum and during labour and delivery. Umbilical cord blood sampling at term can determine fetal platelet count and the need for platelet transfusion, and can aid in deciding the appropriate route of delivery.

Management of severe hemolytic disease with ultrasound-guided intravascular fetal transfusions

Between January 1987 and March 1989, 22 fetuses with severe hemolytic disease were treated with 64 ultrasound-guided intrauterine intravascular transfusions. Eighteen infants survived and are doing well. In 12 fetuses, hydropic changes were present at the first transfusion; 9 of these survived. In 8 of the 10 fetuses with a gestational age less than 26 weeks, intrauterine treatment was successful.

New approaches in the treatment of haemolytic disease of the fetus

The incidence of Rh haemolytic disease of the fetus and newborn complicating pregnancy has fallen since the implementation of prophylaxis with Rh immune globulin. However, occasional mismatched blood transfusions and ineffective or inadequate prophylaxis still result in a few Rh-alloimmunized patients requiring treatment during pregnancy. The development of a safe technique for obtaining pure fetal blood samples has provided the opportunity to assess correctly the severity of anaemia and to study fetal haematology and biochemical parameters, and hence to gain a better understanding of the pathophysiology of this condition. The aim of antenatal management is to predict whether or not the fetus is severely affected, to correct fetal anaemia and to deliver the baby at the optimal time. Fetal IVT is the standard treatment in severe Rh alloimmunization in many centres. However, high volume transfusion without overloading the fetal circulation, as well as increasing the interval between transfusions without jeopardizing the fetal condition, can be achieved by a combination of IVT and IPT. Thus, the total number of transfusions needed and the overall procedure-related risk for each fetus is reduced. With the recent advances in fetal medicine, haematology and neonatology, the survival rate of affected fetuses in some centres is now about 90%. Fetal death will continue to be associated with two sets of circumstances: trauma or complications due to IVT or IPT in early gestation when delivery is not feasible, and late referrals with such severe hydrops that its reversal is not possible. There is still, therefore, a need for research into new methods of treatment, such as high dose intravenous IgG, which can non-invasively diminish fetal red cell destruction.

Twenty-two years of intra-uterine intraperitoneal transfusions

Over a period of 22 years, 154 fetuses were treated with 270 intra-uterine intraperitoneal transfusions. The patients were divided into three groups, according to the period they were treated. The overall percentage of surviving infants increased from 33% during the first period to 58% in the last period. In the group of infants that were not hydropic at the time of the first transfusion, the survival rate increased from 35 to 83%. In the group of children that were hydropic during the first transfusion, the survival rate during the first and last period was 24 and 42%, respectively. The percentage of fetuses that needed their first transfusion before the 26th week of pregnancy increased from 15 to 32% during the study period. Only 13% of these children survived. Lately, the intravascular approach has been introduced. Intravascular transfusions seem to be very effective, especially in early pregnancies and in hydropic fetuses. Application of the two techniques each in the most appropriate situation might offer optimal results for the near future.

Management of serious alloimmunization in pregnancy

In the past 40 years, tremendous advances in the treatment of hemolytic disease have been made. The perinatal mortality has been reduced considerably. Rh immunoprophylaxis has decreased the incidence of Rh immunization to around 6 per 100,000 live births. Nevertheless, treatment of severe hemolytic disease is still essential. Increased reliability of diagnostic procedures have made early detection and optimal treatment of hemolytic disease possible. Treatment by plasmapheresis is still controversial. Although believed to be beneficial by some authors, conclusive evidence of its efficacy has not been obtained. With preterm induction of birth at 32 weeks of gestation, the chances for survival are 95%. Improvement of techniques and the use of modern real-time ultrasound equipment have made intrauterine intraperitoneal transfusion, in experienced hands, a relatively safe and successful procedure. Intravascular transfusion appears beneficial in early pregnancy. Combination of both techniques will probably be the answer for the future. The development of neonatal intensive care facilities has made a major contribution to the survival of children with haemolytic disease. The relative low incidence of haemolytic disease has made it imperative that treatment should take place in centers where experience and special skill are available.

Have Liley charts outlived their usefulness?

Fetal blood and amniotic fluid samples were obtained fetoscopically from 59 rhesus-isoimmunized pregnancies at 18 to 25 weeks' gestation. Fetal hemoglobin was measured and amniotic fluid optical density deviation at a wavelength of 450 nm determined. Two sets of normal reference values for optical density at 450 nm and fetal hemoglobin at 16 to 36 and 16 to 25 weeks were established from 475 amniotic fluid and 153 fetal blood samples obtained from pregnancies not complicated by fetal hemolysis. As expected, there was a significant linear correlation between the degree of fetal anemia and the amniotic fluid optical density at 450 nm in rhesus-isoimmunized pregnancies. However, the values of optical density at 450 nm were widely scattered, thereby limiting their ability to predict accurately the severity of disease in these second-trimester pregnancies. In 25 of the patients, the value of optical density at 450 nm was determined at 6 to 16 days before fetoscopy. The severity of fetal anemia could not be predicted by the trend in optical density at 450 nm. These data suggest that the only reliable method to determine the severity of rhesus isoimmunization in the second trimester of pregnancy is the direct measurement of fetal hemoglobin.