Fetal aneuploidy diagnosed at celocentesis for early prenatal diagnosis of congenital hemoglobinopathies

Introduction: Currently, prenatal diagnosis of genetic disorders requires chorionic villus sampling or amniocentesis carried out after 11 and 16 weeks of gestation, respectively. Celocentesis is a procedure for prenatal diagnosis that could be used from as early as 7 weeks. The present investigation evaluated the feasibility of performing diagnosis for monogenic diseases using celomic fluid containing cells of fetal origin.

Material and methods: Analysis consisted of 489 singleton pregnancies undergoing celocentesis for the prenatal diagnosis of hemoglobinopathies (n = 367) or before surgical termination of pregnancy for social indications (n = 122). Embryo-fetal cells were isolated from celomic fluid using CD71 antibodies or by micromanipulation. Quantitative fluorescent polymerase chain reaction of short tandem repeat sequences of chromosomes 13, 18, 21, X and Y were used to determine the presence of maternal DNA.

Results: 357/489 (73%) of celomic fluid samples were contaminated with maternal cells. In two cases, diagnosis was not possible due to the high contamination of celomic fluid. Eighty-seven (23.8%) fetuses were affected by hemoglobinopathies and, in five cases, chromosomal aneuploidies were found, including three cases of trisomy 21, one of trisomy 13 and one of triploidy. In all cases, the diagnosis of hemoglobinopathies and chromosomal abnormalities was confirmed by molecular and traditional cytogenetic analysis after amniocentesis, chorionic villus or placental tissue collection following pregnancy termination.

Conclusions: The findings of this study demonstrate that embryo-fetal cell selection from celomic fluid allows reliable and early prenatal diagnosis of hemoglobinopathies and can give more information on any fetal aneuploidy following the control of maternal contamination by quantitative fluorescent-PCR.