Very early prenatal diagnosis of genetic diseases based on coelomic fluid analysis: a feasibility study.

BACKGROUND Coelocentesis may represent the ideal technique for very early prenatal diagnosis. Although cell density in coelomic fluid (CF) is very low, the results of analyses on the cellular compartment have been proposed for prenatal diagnosis. METHODS AND RESULTS We aimed to evaluate the amount of total DNA (i.e. cellular and cell-free) in 14 samples (0.4-0.8 ml) of CF, taken from women at 8- to 9-week gestation, who are about to undergo termination of pregnancy, and to assess the feasibility of multiple single-gene analyses using multiplex real-time PCR. We found that the amount of total DNA in the CF was very low and varied widely. Genetic testing using multiplex real-time PCR was successfully achieved in 10 of 14 samples (71%). However, when considering samples that could provide a reliable prenatal diagnosis (i.e. successful PCR analysis and no marked maternal contamination), reliable CF-DNA-based prenatal diagnoses were obtained in only 8 of the 14 (58%) samples. CONCLUSION The development of highly reliable procedures adapted to pauci-cellular CF is crucially needed before coelocentesis could be proposed for early prenatal diagnosis of genetic diseases before 10 weeks.