Chorionic villus sampling (CVS) is a test used for prenatal diagnosis [5]. Safe to perform at an earlier stage in pregnancy [6] than amniocentesis, CVS is another invasive prenatal diagnostic test that can be performed as early as ten weeks after the woman?s last menstrual cycle. While this test does carry some risks, it is generally very effective at predicting heritable diseases during or soo...

Invasive prenatal diagnosis techniques include chorionic villus sampling (CVS), amniocentesis, cordocentesis or percutaneous umbilical blood sampling (PUBS), fetal tissue sampling, as well as embryoscopy and fetoscopy (Table 2). Some diagnostic results may be obtained by more than one technique: for example, fetal karyotype can be obtained from cells from amniocentesis, chorionic villus samplin...

Chorionic villus sampling has gained importance as a tool for early cytogenetic diagnosis with a shift toward first trimester screening. First trimester screening using nuchal translucency and biomarkers is effective for screening. Chorionic villus sampling generally is performed at 10-12 weeks by either the transcervical or transabdominal approach. There are two methods of analysis; the direct...

BACKGROUND First trimester screening (FTS) for Down syndrome combines measurement of nuchal translucency, free beta-human chorionic gonadotrophin and pregnancy-associated plasma protein-A (PAPP-A). The aim of this study was to undertake a detailed analysis of FTS results in singleton pregnancies conceived using assisted reproductive technologies (ART) and non-ART pregnancies. METHODS A record...

Amniocentesis and chorionic villus sampling are tests for the prenatal diagnosis of cytogenetic abnormalities. We calculated the incremental costs per abnormal birth averted, and the incremental costs per quality-adjusted outcome, of amniocentesis and chorionic villus sampling performed for the indication of maternal age. Probabilities were obtained from the literature, and direct medical costs...

OBJECTIVE It was the aim of this study to examine the possible effects of maternal and fetal characteristics on the fetal fraction in maternal plasma cell-free DNA (cfDNA) at 11-13 weeks' gestation. METHODS In a nested case-control study, cfDNA was extracted from maternal plasma obtained before chorionic villous sampling from 300 euploid, 50 trisomy 21 and 50 trisomy 18 pregnancies at 11-13 w...

We show here that at least 5 keratin proteins are present in villous trophoblast and the same 5 in extravillous trophoblast. A further 14 tested were undetectable in these tissues. In contrast, 10 of the 19 keratins tested were present in amniotic epithelium. The marking of amniotic epithelium on the one hand, as distinct from villous and extravillous trophoblast on the other, can be achieved u...