title: First-trimester maternal serum pregnancy-associated plasma protein-A and pre-eclampsia.
abstract: OBJECTIVE
  To examine the relationship between low maternal serum pregnancy-associated plasma protein-A (PAPP-A) and uterine artery pulsatility index (UtA-PI) at 11+0 to 13+6 weeks with subsequent development of pre-eclampsia (PE).
  
  
  METHODS
  UtA-PI and serum PAPP-A were measured in women attending for routine care at 11+0 to 13+6 weeks of gestation. In the population, 156 (1.9%) women developed PE, including 32 (0.4%) in whom delivery was before 34 weeks (early PE) and 124 (1.5%) with delivery at 34 weeks or more (late PE); 7895 (98.1%) women had no PE. Regression analysis was used to examine which of the factors amongst maternal characteristics, log PAPP-A multiples of the median (MoM) and log UtA-PI MoM contributed to the prediction of PE.
  
  
  RESULTS
  The median PAPP-A MoM was 1.002 (interquartile range (IQR), 0.685-1.411) in the unaffected group, 0.555 (IQR, 0.463-0.922) in early PE and 0.911 (IQR, 0.580-1.247) in late PE. Serum PAPP-A was below the 5th centile in 21.9% of early PE and 6.5% of late PE cases. The PAPP-A-related patient-specific risk for PE was strongly influenced by maternal characteristics. There was a significant association between log UtA-PI MoM and log PAPP-A MoM (P=0.001), and the detection rate of screening for PE by maternal variables and UtA-PI was not improved by inclusion of PAPP-A. Regression analysis was used to establish tables that allow modification of the maternal history and PAPP-A-related patient-specific risk for PE by the measurement of UtA-PI.
  
  
  CONCLUSIONS
  Low PAPP-A is a marker for subsequent development of PE. The PAPP-A-related patient-specific risk for PE can be modified by the measurement of UtA-PI.
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: L C Y
authors.initials: LC
authors.lastname: Poon
authors.forename: N
authors.initials: N
authors.lastname: Maiz
authors.forename: C
authors.initials: C
authors.lastname: Valencia
authors.forename: W
authors.initials: W
authors.lastname: Plasencia
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008875:Middle Aged; D048208:Nuchal Translucency Measurement; D011225:Pre-Eclampsia / Q000097:blood / Q000175:diagnosis*; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology*; D014599:Uterus / Q000098:blood supply*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D011266:Pregnancy-Associated Plasma Protein-A