Embryo-fetal erythroid cell selection from celomic fluid allows earlier prenatal diagnosis of hemoglobinopathies

Objective: Celocentesis, which involves aspiration of celomic fluid at 7-9 weeks' gestation, can potentially provide early prenatal diagnosis of single-gene disorders. The main barrier to wide acceptability of this technique is contamination of the sample by maternal cells. This problem can be overcome through selection of embryo-fetal erythroid precursors, which are found in celomatic fluid.

Method: Embryo-fetal erythroid precursors were selected by an anti-CD71 MicroBeads method or by direct micromanipulator pickup of the cells selected on the basis of their morphology.

Results: In our series of 302 singleton pregnancies at high risk for hemoglobinopathies, Celocentesis provided a sample of celomic fluid in all cases. In 100 (33.1%) samples, maternal contamination was absent or very low (< 5%), and unambiguous results were obtained without the need for any preliminary procedures. In 160 (53%) cases, the contamination was between 5% and 60%, and selection of embryo-fetal erythroid precursors was successfully achieved by anti-CD71 MicroBeads. In 42 (13.9%) cases, the contamination was > 60%, and selection of embryo-fetal cells was achieved by micromanipulation. In all 302 cases, there was concordance between DNA obtained from celomic fluid samples and fetal or newborn DNA.

Conclusions: Celocentesis can be a reliable procedure for earlier prenatal diagnosis of fetal monogenic diseases.