title: Cell-Free Placental DNA in Maternal Plasma in Relation to Placental Health and Function.
abstract: BACKGROUND
  While cell-free placental DNA (cfp-DNA) increases in response to certain pathological conditions, confounding variables, such as placental size, may also contribute to its release. Furthermore, the relationship between cfp-DNA and maternal serum proteins has not been well investigated.
  
  
  OBJECTIVE
  To analyze plasma cfp-DNA levels and correlate with measurable placental parameters, maternal serum proteins, or pathologic conditions reflecting placental dysfunction.
  
  
  METHODS
  Methylated fraction of RASSF1A was quantified in maternal plasma as a measure of cfp-DNA in a cohort of 86 pregnant women.
  
  
  RESULTS
  Placental dimensions or weight had no impact on cfp-DNA levels in noncomplicated pregnancies (n = 63). However, an association between β-hCG and cfp-DNA levels (p = 0.0012) was detected. Complications occurred in 23 pregnancies including chromosomal abnormalities, gestational hypertension, intrauterine growth restriction, and preterm birth. There was overall a skewed distribution (<-1 SD or >1 SD from mean) for cfp-DNA in the abnormal group, although due to the small number of samples for each pathology, we provide only descriptive data to assess possible trends in cfp-DNA variation.
  
  
  CONCLUSIONS
  While cfp-DNA levels outside of the normal range may reflect placental distress, this relationship may be masked by a number of physiological confounders. The independence of cfp-DNA from β-hCG levels commonly assessed in pregnancy need to be further addressed.
authors: Child and Family Research Institute, and Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, B.C., Canada.
authors: Irina
authors: I
authors: Manokhina
authors: Tanjot K
authors: TK
authors: Singh
authors: Wendy P
authors: WP
authors: Robinson
mesh_terms: D015415:Biomarkers / Q000097:blood*; D000073888:Cell-Free Nucleic Acids / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D062145:Maternal Serum Screening Tests / Q000379:methods*; D010920:Placenta / Q000502:physiology*; D010949:Plasma / Q000378:metabolism*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D000073888:Cell-Free Nucleic Acids
keywords: Cell-free DNA; Intrauterine growth restriction; Preeclampsia; Pregnancy; Prenatal screening; Preterm birth