[Use of peak systolic velocity in the middle cerebral artery after serial intravenous fetal exchange transfusions in the end of pregnancy]. / Intérêt du pic systolique de vélocité dans l'artère cérébrale moyenne en fin de grossesse après exsanguino-transfusions itératives.

OBJECTIVES: Our aim was to assess the efficiency of the peak systolic velocity in the middle cerebral artery (PSV-MCA) to predict neonatal anemia at the end of pregnancies after serial intravenous fetal exchange transfusions (IFET) for red-cell fetomaternal immunization. PATIENTS AND METHODS: We conducted a retrospective study from 01/01/2004 to 31/12/2009 of 25 pregnancies after IFET for red-cell fetomaternal immunization, in Saint Vincent de Paul Hospital, Paris. The study assessed correlation between the last prenatal PSV-MCA measured and hemoglobin concentration at birth and other neonatal data. RESULTS: Last prenatal PSV-MCA and hemoglobin concentration at birth were significantly correlated (r=-0.39, P<0.01). CONCLUSION: There is a good correlation between last PSV-MCA measured before birth and neonatal haemoglobin and complexity of neonatal care linked to anemia. Cerebral Doppler is useful for the follow-up of pregnancies at risk for anemia even in the end of the pregnancy and after serial intravenous fetal exchange transfusions.

[Kell alloimmunization in pregnancy]. / Allo-immunisation anti-Kell et grossesse.

INTRODUCTION: Kell alloimmunization is a rare disease, although its incidence is the highest after after anti-D alloimmunization. METHODS: We report two recent cases and a review of the literature to describe practical management of Kell alloimmunization in pregnancy. DISCUSSION: When an immunization against the Kell antigen was diagnosed, amniocentesis was performed at 14 weeks gestation to determine the fetal blood group. If the fetus was Kell positive, a first fetal blood sample was drawn at 17 weeks gestation in case of fetal hydrops, and at 20 weeks without fetal hydrops. The diagnosis of anemia led to in utero transfusion. A second fetal blood sample was taken at 8 to 10 days, every two weeks during the second trimester and every three or four weeks during the third trimester. Fetal well-being was assessed with weekly sonography and rates of hemoglobin decline. These measures enable adapting the frequency of fetal blood sampling.

Management and outcome of fetomaternal Rh alloimmunization in twin pregnancies.

Between 1987 and 1996, nine twin pregnancies with fetomaternal Rh alloimmunization were delivered at our institution. Eight pregnancies were dizygotic, and the fetal blood groups were different in 3 cases. The remaining pregnancy was monozygotic and monochorionic-diamniotic. Intravenous fetal exchange transfusion was performed in five pregnancies, up to five times in each twin in one pregnancy. No fetal death occurred. The average gestational age at birth was 35 (range 33-37) weeks. The hemoglobin level was 13.2 (range 9.2-16.5) g/dl. Fetomaternal Rh alloimmunization in twin pregnancy is according to zygosity; each fetus has to be treated separately, except in case of transplacental communication.

[Parvovirus B19 infection and pregnancy]. / Infection à parvovirus B19 et grossesse.

Parvovirus B19 was identified in 1975. It causes infections megalerythemia in adults associated with skin eruptions and joint pain (about 50% of the adult population is immunized). The risk of contamination in case of an epidemia is high in school teachers and school personnel. In 1984, the parvovirus B19 was implicated as the cause of fetal anasarca. The risk of transplacental contamination is estimated at 33% in case of maternal infection. Pregnant women with parvovirus B19 infection and confirmed serology should have an echography every 15 days. Fetal anasarca can be complicated by in utero fetal death related to erythroid stem-cell anaemia. The diagnosis of fetal infection is based on PCR techniques on fetal blood. Symptomatic antenatal treatment with in utero transfusion was proposed as early as 1988. This method does not however appear to be necessary in all cases as the outcome in several reports of untreated fetuses was delivery of a normal child. There is the possibility of myocardial damage caused by parvovirus B19 which would make in utero transfusion difficult and limit its beneficial effect. Finally associated thrombopenia is often severe and increased fetal risk.

Presence of gamma interferon in human acute and congenital toxoplasmosis.

The production of gamma interferon in acute acquired and congenital toxoplasmosis was studied. Gamma interferon was produced at significant titers (P less than 0.001) in the course of both congenital toxoplasmosis and acquired toxoplasmosis at an early stage of infection, when Toxoplasma gondii was multiplying. Its presence in fetal blood was correlated with the positive inoculation of fetal blood or amniotic fluid into mice (95%). The data suggest that the fetus is able to synthesize gamma interferon as early as week 21 of pregnancy. This test, easily and rapidly performed, could be included among those useful for diagnosing fetal toxoplasmic disease.

Two hundred intrauterine exchange transfusions in severe blood incompatibilities.

Two hundred intrauterine exchange transfusions were performed under local anesthesia in 107 cases of blood incompatibilities (60 fetuses with severe anemia and 47 with hydrops). Under sonographic guidance, depending on fetal and placental position, an optimal puncturing site was selected along the umbilical vein: placental insertion, fetal insertion, or fetal intraabdominal segment. Tests were immediately performed to confirm fetal origin of blood obtained and estimate hemoglobin level. Blood used for exchange transfusion was compatible with maternal blood and had a hematocrit value of 75%. Exchange transfusion was continued until a hemoglobin level of 16 gm/dl was reached. This procedure was first associated with intraperitoneal transfusions and was subsequently used independently once a month to maintain an adequate hemoglobin level. In 4 fetuses with hydrops, antenatal regression of this sign was observed in 33 cases (70.2%). Overall outcome of 107 fetuses after exchanges was 84 living neonates (78.5%), 15 deaths in utero, and eight neonatal deaths. The survival rate was 91.6% for fetuses without hydrops and 61.7% for those with hydrops. The advantage of exchange transfusion appears to be rapid and efficient correction of anemia with elimination of incompatible fetal red blood cells.

[Preparation of maternal platelets collected by separator for use in fetal transfusion in a case of alloimmunization by anti-PLA1]. / Préparation de plaquettes maternelles collectées sur séparateur de cellules en vue d'une transfusion foetale dans un cas d'allo-immunisation par anti-PLA1.

In one case of fetal thrombocytopenia due to maternal immunization against PLA1 fetal platelet antigen, maternal platelets were collected by automated plasmapheresis. The platelets were collected 24 hours before fetal transfusion at 28, 29, 31 and 36 weeks of gestation. The maternal platelets were irradiated and concentrated in a small volume (7.10(10) to 1,4.10(11) plts in less than 20 ml maternal plasma) a few hours before transfusion. When prepared as described, maximal and irreversible platelet aggregation is obtained with 20 microM of ADP and the pH is over 6, 5-6 hours after concentration. The amounts of transfused platelets were determined to increase theoretically fetal platelet counts over 200,000 plts/mm3. The fetal platelet counts, determined immediately after transfusion, showed an increase of 100,000 plts/mm3. Prenatal fetal transfusion of maternal platelets is available to avoid fetal bleeding during delivery, and during the early neonatal period.

[Immunization against the ZWa (PLA1) platelet antigen: group at risk, prevention of complications. Apropos of 132 cases]. / L'immunisation contre l'antigène plaquettaire ZWa (PLA1): groupe à risque, prévention des complications. A propos de 132 cas.

The identification of anti-ZWa (-PLA1) alloimmunisation is not very frequent. It can be observed in most perinatal alloimmune thrombocytopenias (PAT) and rare post transfusional purpuras (PTP). On the other hand, the clinical consequences of these immunisations are often dramatic, particularly for the foetuses for which there has been no prevention so far. The retrospective study of 132 cases, 123 PAT and 9 PTP, shows the possible irreversible complications for 18% of the newborns with PAT, but especially for 10% of the foetuses which will show PAT at birth. HLA markers are very useful to detect the people who are likely to develop an anti-PLA1 immunization for they are PLA1 negative and HLA DR3. Then, it becomes possible to prevent the complications of these immunisations. It is what we tried to do through the diagnosis and the treatment of PAT in 3 foetuses.

[The present state of prevention of rhesus immunisation (author's transl)]. / Prévention actuelle de l'immunisation Rhésus.

Rhesus factor immunisation and its complications should disappear if the indications and the techniques for abolishing it are followed. The indications follow from the usual mechanism by which immunisation occurs. This is the passage of Rh positive fetal red blood cells into the maternal circulation where they are detected by Kleihauer's test. If in pregnancy uterine bleeding, of accidental trauma occur or if amniocentesis, versions, operations on the pregnant uterus are performed or intrauterine death occurs, the necessary preventive action has to be performed on a rhesus negative woman. When pregnancy comes to an end, be it because of delivery at term when every rhesus negative woman who has not been immunised has to be treated (if the infant is rhesus positive) so the same applies after spontaneous abortion, extra-uterine pregnancy and especially after therapeutic termination of pregnancy after which it is often forgotten. The technique is simple: Within 72 hours a dose of 85 micrograms of anti D globulin is enough if injected intravenously or intramuscularly. Sometimes this quantity has to be increased, however, when the Kleihauer test has shown that more than 5 ml of rhesus positive blood has passed into the maternal circulation, or if blood of the wrong group has been transfused. The dose to neutralise 1 ml of blood is 10 micrograms.