title: The Norwegian preeclampsia family cohort study: a new resource for investigating genetic aspects and heritability of preeclampsia and related phenotypes.
abstract: BACKGROUND
  Preeclampsia is a major pregnancy complication without curative treatment available. A Norwegian Preeclampsia Family Cohort was established to provide a new resource for genetic and molecular studies aiming to improve the understanding of the complex pathophysiology of preeclampsia.
  
  
  METHODS
  Participants were recruited from five Norwegian hospitals after diagnoses of preeclampsia registered in the Medical birth registry of Norway were verified according to the study's inclusion criteria. Detailed obstetric information and information on personal and family disease history focusing on cardiovascular health was collected. At attendance anthropometric measurements were registered and blood samples were drawn. The software package SPSS 19.0 for Windows was used to compute descriptive statistics such as mean and SD. P-values were computed based on t-test statistics for normally distributed variables. Nonparametrical methods (chi square) were used for categorical variables.
  
  
  RESULTS
  A cohort consisting of 496 participants (355 females and 141 males) representing 137 families with increased occurrence of preeclampsia has been established, and blood samples are available for 477 participants. Descriptive analyses showed that about 60% of the index women's pregnancies with birth data registered were preeclamptic according to modern diagnosis criteria. We also found that about 41% of the index women experienced more than one preeclamptic pregnancy. In addition, the descriptive analyses confirmed that preeclamptic pregnancies are more often accompanied with delivery complications.
  
  
  CONCLUSIONS
  The data and biological samples collected in this Norwegian Preeclampsia Family Cohort will provide an important basis for future research. Identification of preeclampsia susceptibility genes and new biomarkers may contribute to more efficient strategies to identify mothers "at risk" and contribute to development of novel preventative therapies.
authors.affiliation: Department of Laboratory Medicine, Children's and Women's Health, the Norwegian University of Science and Technology (NTNU), 7491, Trondheim, Norway. linda.tommerdal@ntnu.no.|Central Norway Regional Health Authority, 7501, Stjørdal, Norway. linda.tommerdal@ntnu.no.
authors.forename: Linda Tømmerdal
authors.initials: LT
authors.lastname: Roten
authors.affiliation: Department of Obstetrics and Gynecology, Haukeland University Hospital, 5058, Bergen, Norway. liv.vestrheim@uib.no.|Department of Clinical Medicine, University of Bergen, 5020, Bergen, Norway. liv.vestrheim@uib.no.
authors.forename: Liv Cecilie Vestrheim
authors.initials: LC
authors.lastname: Thomsen
authors.affiliation: The Regional Biobank of Central Norway, St. Olavs Hospital, Trondheim, Norway. astrid.solberg.gundersen@stolav.no.|Department of Cancer Research and Molecular Medicine, NTNU, 7491, Trondheim, Norway. astrid.solberg.gundersen@stolav.no.
authors.forename: Astrid Solberg
authors.initials: AS
authors.lastname: Gundersen
authors.affiliation: Department of Cancer Research and Molecular Medicine, NTNU, 7491, Trondheim, Norway. Mona.Hoyseter.Fenstad@stolav.no.|Department of Immunology and Transfusion Medicine, St. Olavs Hospital, 7006, Trondheim, Norway. Mona.Hoyseter.Fenstad@stolav.no.
authors.forename: Mona Høysæter
authors.initials: MH
authors.lastname: Fenstad
authors.affiliation: Department of Cancer Research and Molecular Medicine, NTNU, 7491, Trondheim, Norway. marialisaodland@gmail.com.
authors.forename: Maria Lisa
authors.initials: ML
authors.lastname: Odland
authors.affiliation: Department of Laboratory Medicine, Children's and Women's Health, the Norwegian University of Science and Technology (NTNU), 7491, Trondheim, Norway. kristin.m.strand@ntnu.no.
authors.forename: Kristin Melheim
authors.initials: KM
authors.lastname: Strand
authors.affiliation: Department of Obstetrics and Gynecology, Levanger Hospital, 7601, Levanger, Norway. Per.Solberg@helse-nordtrondelag.no.
authors.forename: Per
authors.initials: P
authors.lastname: Solberg
authors.affiliation: Department of Obstetrics and Gynecology, St. Olavs Hospital, 7006, Trondheim, Norway. christian.tappert2@stolav.no.
authors.forename: Christian
authors.initials: C
authors.lastname: Tappert
authors.affiliation: Department of Obstetrics and Gynecology, St. Olavs Hospital, 7006, Trondheim, Norway. elisabeth.araya@stolav.no.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Araya
authors.affiliation: Department of Obstetrics and Gynecology, Stavanger University Hospital, 4068, Stavanger, Norway. gunhild@forusakutten.nhn.no.
authors.forename: Gunhild
authors.initials: G
authors.lastname: Bærheim
authors.affiliation: Department of Obstetrics and Gynecology, Stavanger University Hospital, 4068, Stavanger, Norway. ingvill.lyslo@sus.no.
authors.forename: Ingvill
authors.initials: I
authors.lastname: Lyslo
authors.affiliation: Department of Obstetrics and Gynecology, Stavanger University Hospital, 4068, Stavanger, Norway. kjersti.tollaksen@sus.no.
authors.forename: Kjersti
authors.initials: K
authors.lastname: Tollaksen
authors.affiliation: Department of Obstetrics and Gynecology, Haukeland University Hospital, 5058, Bergen, Norway. line.bjorge@uib.no.|Department of Clinical Medicine, University of Bergen, 5020, Bergen, Norway. line.bjorge@uib.no.
authors.forename: Line
authors.initials: L
authors.lastname: Bjørge
authors.affiliation: Department of Cancer Research and Molecular Medicine, NTNU, 7491, Trondheim, Norway. rigmor.austgulen@ntnu.no.
authors.forename: Rigmor
authors.initials: R
authors.lastname: Austgulen
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009664:Norway / Q000453:epidemiology; D010641:Phenotype; D011225:Pre-Eclampsia / Q000453:epidemiology* / Q000235:genetics*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D012042:Registries / Q000706:statistics & numerical data; D012307:Risk Factors; D044465:White People / Q000235:genetics*; D055815:Young Adult