title: Cell-free fetal DNA in maternal circulation after chorionic villous sampling.
abstract: OBJECTIVE
  This study aims to estimate whether chorionic villous sampling (CVS) causes a significant increase of cell-free fetal DNA (cffDNA) in maternal circulation.
  
  
  METHODS
  Fifty pregnant women with singleton pregnancy were recruited prior to CVS. Maternal peripheral blood was collected before and after CVS. A methylation-sensitive restriction enzyme digestion was used to select the placental-derived hypermethylated promoter of the RASSF1A gene in maternal plasma, thus differentiating cffDNA from mother's cell-free DNA (cfDNA), where the RASSF1A gene is normally hypomethylated. Total cfDNA and cffDNA amounts were compared before and after CVS in each patient. Data were compared using the Student t-test.
  
  
  RESULTS
  No significant difference before and after CVS was found between the following: (i) total cfDNA concentration in plasma (p = 0.695); (ii) cffDNA concentration in plasma (p = 0.612); and (iii) percentage of fetal DNA in plasma (p = 0.835). After dividing the cases on the basis of the sex of the fetus, maternal age, gestational age, number of pregnancies, position of the placenta, and presence of trisomy of the fetus, no difference in fetal and total DNA concentrations before and after CVS was observed.
  
  
  CONCLUSIONS
  The CVS does not seem to significantly disrupt the maternal-placental interface, as no significant increase of cffDNA in maternal plasma following CVS was observed.
authors: Department of Science for Child and Woman's Health, University of Florence, Florence, Italy. mariarosaria.ditommaso@unifi.it
authors: Mariarosaria
authors: M
authors: Di Tommaso
authors: Viola
authors: V
authors: Seravalli
authors: Francesca
authors: F
authors: Salvianti
authors: Cecilia
authors: C
authors: Bussani
authors: Lucia
authors: L
authors: Pasquini
authors: Adalgisa
authors: A
authors: Cordisco
authors: Pamela
authors: P
authors: Pinzani
mesh_terms: D015193:Chorionic Villi Sampling / Q000009:adverse effects*; D004247:DNA / Q000097:blood*; D019175:DNA Methylation; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005331:Fetomaternal Transfusion / Q000097:blood / Q000209:etiology; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D010298:Parity; D010920:Placenta / Q000737:chemistry; D011247:Pregnancy; D011401:Promoter Regions, Genetic / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D025521:Tumor Suppressor Proteins / Q000235:genetics
chemical_list: C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins; D004247:DNA