title: Pregnancy outcome for fetuses with increased nuchal translucency but normal karyotype.
abstract: OBJECTIVE
  To investigate pregnancy outcome for fetuses with nuchal translucency (NT) ≥3.5 mm but normal karyotype in the Stockholm (Sweden) area.
  
  
  METHODS
  A retrospective population-based cohort study. From 2006 to 2012, fetal NT was measured in 55123 singleton pregnancies. There were 341 pregnancies with NT thickness ≥3.5 mm; 139 had a normal karyotype, 164 had an abnormal karyotype and 38 were removed from the study. Pregnancy outcome was defined as adverse (termination of pregnancy [TOP], miscarriage [MC], intrauterine fetal death [IUFD], or delivery of a child with structural defects or genetic disorders), or favourable (delivery of a child without any structural defects or genetic disorders diagnosed before discharge).
  
  
  RESULTS
  Of the 139 high NT pregnancies with normal karyotype, 110 (79.2%) resulted in live births, one (0.7%) IUFD, 23 (16.5%) TOP and five (3.6%) MC. The risk of an adverse pregnancy outcome increased with increasing NT. Structural fetal defects were found in 28 (19.5%) of pregnancies undergoing second trimester ultrasound screening, of which seven resulted in live births and 21 were terminated. The most common structural defect was cardiac defects.
  
  
  CONCLUSIONS
  Adverse pregnancy outcome increased with increasing NT, even with normal karyotype, however, the prognosis is good if the second trimester ultrasound screening is normal.
authors.affiliation: Karolinska Institutet, Division of Translational Alzheimer Neurobiology, Department of Neurobiology, Care Sciences and Society, Novum floor 4, 141 57 Stockholm, Sweden.
authors.forename: Christina Unger
authors.initials: CU
authors.lastname: Lithner
authors.affiliation: Karolinska University Hospital, Department of Obstetrics and Gynecology, Center of Fetal Medicine, 14186 Stockholm, Sweden.
authors.forename: Marius
authors.initials: M
authors.lastname: Kublickas
authors.affiliation: Karolinska University Hospital, Department of Obstetrics and Gynecology, Center of Fetal Medicine, 14186 Stockholm, Sweden Sverker.Ek@karolinska.se.
authors.forename: Sverker
authors.initials: S
authors.lastname: Ek
mesh_terms: D000028:Abortion, Induced / Q000706:statistics & numerical data*; D000022:Abortion, Spontaneous / Q000453:epidemiology*; D000013:Congenital Abnormalities / Q000453:epidemiology; D005260:Female; D005313:Fetal Death; D005333:Fetus; D030342:Genetic Diseases, Inborn / Q000453:epidemiology*; D006330:Heart Defects, Congenital / Q000453:epidemiology*; D006801:Humans; D007231:Infant, Newborn; D059785:Karyotype; D008297:Male; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011262:Pregnancy Trimester, Second; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology
keywords: Congenital defect; Karyotype; Nuchal translucency; Pregnancy outcome; Prenatal Diagnosis