Cerebral Doppler velocimetry to predict fetal anemia after more than three intravenous fetal exchange transfusions.

BACKGROUND: We aimed to assess usefulness of the middle cerebral artery peak systolic velocity (MCA-PSV) in the prediction of fetal anemia after more than three intravenous fetal-exchange transfusions (IFET). STUDY DESIGN AND METHODS: A retrospective study was conducted over 6 years of 15 consecutive pregnancies with severe red blood cell fetomaternal alloimmunization requiring more than three IFETs. We evaluated correlation between MCA-PSV (expressed as multiples of the mean [MoM]) and pretransfusion hemoglobin (Hb) in the fetus (MoM). Analyses were also performed to assess the value of MCA-PSV to predict moderate to severe fetal anemia. RESULTS: Twenty-seven MCA-PSV measurements performed before the fourth to last IFET were coupled with pretransfusion Hb in the fetus. The median number of IFETs per fetus was five (range, four to eight). Five Hb samples found fetuses with severe (19%), seven with moderate (26%), and 15 with mild anemia (56%). There was a linear correlation between MCA-PSV(x) and Hb in the fetus(y): y = -0.21x + 0.93 (r = -0.50, p < 0.01). For the prediction of moderate to severe anemia the negative predictive value of MCA-PSV with a threshold of 1.5 MoM was 75%, positive predictive value 73%, specificity 80%, sensibility 67%, and positive likelihood ratio 3.33. The area under the receiver operating characteristic curve was 0.78 (95% confidence interval, 0.59-0.96; p < 0.001). For the prediction of severe anemia, MCA-PSV with a threshold of 1.5 MoM had 94% negative predictive value, 80% sensibility, and a positive likelihood ratio of 2.5. CONCLUSIONS: This study shows that a correlation between MCA-PSV and Hb in the fetus persists even after more than three IFETs. MCA-PSV measurements thus remain useful to monitor fetuses at risk of anemia.

Intravenous fetal exchange transfusion before 22 weeks of gestation in early and severe red-cell fetomaternal alloimmunization.

OBJECTIVES: To determine the perinatal outcome in severe red-cell fetomaternal alloimmunization. METHODS: Retrospective series of 32 affected fetuses treated with intravenous fetal exchange transfusion (IFET) before 22 weeks of gestation. The main outcome measures were the degree of fetal anemia, fetal transfusions and perinatal outcome. RESULTS: The first IFET was performed at 19.8 +/- 1.8 weeks of gestation. All fetuses were severely anemic and hemoglobin levels were not different between 20 hydropic and 12 nonhydropic fetuses (4.1 +/- 2.5 vs. 5.6 +/- 2.8 g/dl, p=0.33). The initial maternal anti-D level ranged from 4 to 76 microg/l and was not correlated to fetal anemia (r=-0.07). CONCLUSION: The overall perinatal survival rate was 78% compared to a previous perinatal loss rate excluding first pregnancies of 55.5%.

Sub-lethal hydrops as a manifestation of dehydrated hereditary stomatocytosis in two consecutive pregnancies.

Dehydrated hereditary stomatocytosis (DHS) is a rare congenital hemolytic anemia mapping to 16q23-q24. We showed recently that it is part of a pleiotropic syndrome likely to display pseudohyperkalemia and/or different forms of fetal and placental fluid collections. Here, we report a woman with DHS. She had two consecutive pregnancies associated with severe fetal hydrops. Hydrops would probably have been lethal in the absence of appropriate removal of ascites and excess amniotic fluid. In utero exchange transfusion, performed once, was useless, because anemia was not pronounced enough to be the cause of the hydrops. In both newborns, ascites resolved within a week following birth and never recurred. The association of hydrops and hemolytic anemia suggests the possibility of DHS. Symptomatic treatment of the hydrops assists survival until spontaneous resorption occurs.