title: High-resolution profiling of fetal DNA clearance from maternal plasma by massively parallel sequencing.
abstract: BACKGROUND
  With the advent of massively parallel sequencing (MPS), DNA analysis can now be performed in a genomewide manner. Recent studies have demonstrated the high precision of MPS for quantifying fetal DNA in maternal plasma. In addition, paired-end sequencing can be used to determine the size of each sequenced DNA fragment. We applied MPS in a high-resolution investigation of the clearance profile of circulating fetal DNA.
  
  
  METHODS
  Using paired-end MPS, we analyzed serial samples of maternal plasma collected from 13 women after cesarean delivery. We also studied the transrenal excretion of circulating fetal DNA in 3 of these individuals by analyzing serial urine samples collected after delivery.
  
  
  RESULTS
  The clearance of circulating fetal DNA occurred in 2 phases, with different kinetics. The initial rapid phase had a mean half-life of approximately 1 h, whereas the subsequent slow phase had a mean half-life of approximately 13 h. The final disappearance of circulating fetal DNA occurred at about 1 to 2 days postpartum. Although transrenal excretion was involved in the clearance of circulating fetal DNA, it was not the major route. Furthermore, we observed significant changes in the size profiles of circulating maternal DNA after delivery, but we did not observe such changes in circulating fetal DNA.
  
  
  CONCLUSIONS
  MPS of maternal plasma and urinary DNA permits high-resolution study of the clearance profile of circulating fetal DNA.
authors.affiliation: Centre for Research into Circulating Fetal Nucleic Acids, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
authors.forename: Stephanie C Y
authors.initials: SC
authors.lastname: Yu
authors.forename: Shara W Y
authors.initials: SW
authors.lastname: Lee
authors.forename: Peiyong
authors.initials: P
authors.lastname: Jiang
authors.forename: Tak Y
authors.initials: TY
authors.lastname: Leung
authors.forename: K C Allen
authors.initials: KC
authors.lastname: Chan
authors.forename: Rossa W K
authors.initials: RW
authors.lastname: Chiu
authors.forename: Y M Dennis
authors.initials: YM
authors.lastname: Lo
mesh_terms: D001724:Birth Weight; D002585:Cesarean Section; D004247:DNA / Q000097:blood* / Q000652:urine; D005260:Female; D005333:Fetus; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007700:Kinetics; D049590:Postpartum Period; D011247:Pregnancy; D013997:Time Factors
chemical_list: D004247:DNA