title: Quantitative analysis of fetal DNA in maternal plasma and serum: implications for noninvasive prenatal diagnosis.
abstract: We have developed a real-time quantitative PCR assay to measure the concentration of fetal DNA in maternal plasma and serum. Our results show that fetal DNA is present in high concentrations in maternal plasma, reaching a mean of 25.4 genome equivalents/ml (range 3.3-69. 4) in early pregnancy and 292.2 genome equivalents/ml (range 76. 9-769) in late pregnancy. These concentrations correspond to 3.4% (range 0.39%-11.9%) and 6.2% (range 2.33%-11.4%) of the total plasma DNA in early and late pregnancy, respectively. Sequential follow-up study of women who conceived by in vitro fertilization shows that fetal DNA can be detected in maternal serum as early as the 7th wk of gestation and that it then increases in concentration as pregnancy progresses. These data suggest that fetal DNA can be readily detected in maternal plasma and serum and may be a valuable source of material for noninvasive prenatal diagnosis.
authors.affiliation: Department of Chemical Pathology, The University of Hong Kong, Prince Wales Hospital, Shatin, New Territories, Hong Kong. loym@cuhk.edu.hk
authors.forename: Y M
authors.initials: YM
authors.lastname: Lo
authors.forename: M S
authors.initials: MS
authors.lastname: Tein
authors.forename: T K
authors.initials: TK
authors.lastname: Lau
authors.forename: C J
authors.initials: CJ
authors.lastname: Haines
authors.forename: T N
authors.initials: TN
authors.lastname: Leung
authors.forename: P M
authors.initials: PM
authors.lastname: Poon
authors.forename: J S
authors.initials: JS
authors.lastname: Wainscoat
authors.forename: P J
authors.initials: PJ
authors.lastname: Johnson
authors.forename: A M
authors.initials: AM
authors.lastname: Chang
authors.forename: N M
authors.initials: NM
authors.lastname: Hjelm
mesh_terms: D004247:DNA / Q000097:blood*; D005260:Female; D005333:Fetus / Q000502:physiology; D006801:Humans; D008297:Male; D008431:Maternal-Fetal Exchange; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy / Q000097:blood* / Q000235:genetics; D011296:Prenatal Diagnosis / Q000379:methods*; D012730:Sex Chromosomes / Q000235:genetics
chemical_list: D004247:DNA