title: Incidence of preeclampsia in pregnant Swiss women.
abstract: OBJECTIVE
  The epidemiology of preeclampsia in Switzerland is known only from a retrospective registry study. This analysis aimed to prospectively determine the incidence of preeclampsia in a cohort of pregnant women in Switzerland.
  
  
  METHODS
  Pregnant women presenting at gestational week 11-14 at their obstetrician's office were consecutively included and prospectively followed-up until the end of pregnancy. Ultrasound characteristics, blood pressure measurements, body mass index, and personal history were recorded. Duration of pregnancy, occurrence of preeclampsia, birth weight and Apgar scores were recorded as outcomes.
  
  
  RESULTS
  There were 1,300 pregnancies with follow-up available for analysis. Median age was 30 years (interquartile range [IQR] 27-33), median body mass index (BMI) 23.3 kg/m² (IQR 21.2-26.1), median systolic blood pressure 117 mm Hg (IQR 109-126) and median diastolic blood pressure 70 mm Hg (IQR 64-77). A total of 30 women developed preeclampsia, corresponding to an incidence of 2.31% (95% confidence interval [CI] 1.62%-3.28%). Of the women with preeclampsia, 6.66% (95% CI 2.04%-21.42%) had early-onset preeclampsia, 13.33% (95% CI 5.45%-29.83%) progressed to eclampsia, whereas 10% (95% CI 3.63%-28.75%) developed HELLP syndrome (haemolysis, elevated liver enzymes, low platelet count). Nulliparity and prior history of preeclampsia were more frequently seen in pregnancies with preeclampsia than in pregnancies without preeclampsia. BMI, as well as systolic and diastolic blood pressure were higher in pregnancies subsequently developing preeclampsia.
  
  
  CONCLUSIONS
  The incidence of preeclampsia in Switzerland is in line with frequencies observed elsewhere in the world. Extrapolation to a national level indicates that about 1,911 (range 1,340-2,713) preeclampsia cases per year can be expected to occur in Switzerland.
authors.affiliation: Labormedizinisches Zentrum Dr. Risch, Liebefeld, Switzerland.
authors.forename: Mette-Triin
authors.initials: MT
authors.lastname: Purde
authors.affiliation: Department of Obstetrics and Gynaecology, Inselspital, University of Bern, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Baumann
authors.affiliation: Labormedizinisches Zentrum Dr. Risch, Liebefeld, Switzerland.
authors.forename: Ute
authors.initials: U
authors.lastname: Wiedemann
authors.affiliation: Labormedizinisches Zentrum Dr. Risch, Liebefeld, Switzerland.
authors.forename: Urs E
authors.initials: UE
authors.lastname: Nydegger
authors.affiliation: Labormedizinisches Zentrum Dr. Risch, Liebefeld, Switzerland, and Division of Clinical Biochemistry, Medical University Innsbruck, Austria.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Risch
authors.affiliation: Department of Obstetrics and Gynaecology, Inselspital, University of Bern, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Surbek
authors.affiliation: Division of Clinical Biochemistry, Medical University Innsbruck, Austria, and Zentrallabor, Kantonsspital, Chur, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Risch
mesh_terms: D000328:Adult; D001794:Blood Pressure; D015992:Body Mass Index; D004461:Eclampsia; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D010298:Parity; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011295:Prenatal Care; D011446:Prospective Studies; D012307:Risk Factors; D013557:Switzerland / Q000453:epidemiology