First-trimester non-invasive prenatal diagnosis of triploidy

We report a case of fetal triploidy in which fetal nucleated red blood cell s were isolated from the maternal peripheral circulation at 12 weeks' gesta tion. FISH analysis with X and Y specific probes revealed three hybridizati on signals for the X chromosomes in 14 cells. The karyotype as established after CVS was shown to be 69,XXX. Two other non-invasive first-trimester sc reening methods were also evaluated. The serum markers pregnancy-associated plasma protein A (PAPP-A) and the free beta-chain of chorionic gonadotroph in (free beta-hCG) were both shown to be decreased in the same blood sample . An enlarged nuchal translucency (5 mm greater than or equal to 95th centi le) was seen at 13 +2 weeks of gestation. Copyright (C) 1999 John Wiley & S ons, Ltd.