title: First trimester cystic hygroma: does early detection matter?
abstract: OBJECTIVE
  To describe the association of abnormal outcomes with fetal cystic hygroma detected when crown-rump length measures less than 45 mm, and to compare them to outcomes among fetuses with cystic hygroma detected when crown-rump length measures 45-84 mm.
  
  
  METHODS
  We performed a retrospective cohort study of fetuses with first trimester nuchal cystic hygroma from 2005 to 2015.
  
  
  RESULTS
  A total of 212 fetuses were included. Abnormal karyotype was found in 20 of 46 (43.4%) fetuses with cystic hygroma detected when crown-rump length measured below 45 mm, compared to 108 of 148 (73%) fetuses with cystic hygroma detected at crown-rump lengths of 45-84 mm (p = 0.001). There were no differences in rates of major structural anomaly (27% vs 36%; p = 0.53) or pregnancy loss (23% vs 7%; p = 0.22) among fetuses with normal karyotype. Those with cystic hygroma diagnosed at crown-rump lengths below 45 mm were more likely to have a normal neonatal outcome compared to cases diagnosed with crown-rump lengths of 45-84 mm (25% vs 11%; p = 0.02).
  
  
  CONCLUSIONS
  Cystic hygroma detected when crown-rump length measures below 45 mm have lower rates of chromosomal abnormalities and a higher proportion of normal birth outcomes when compared to those detected later in the first trimester. © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Obstetrics and Gynecology, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Scholl
authors.affiliation: Department of Obstetrics and Gynecology, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Chasen
mesh_terms: D059786:Abnormal Karyotype / Q000706:statistics & numerical data*; D000328:Adult; D002869:Chromosome Aberrations; D002887:Chromosomes, Human, Pair 18; D015331:Cohort Studies; D018568:Crown-Rump Length; D004314:Down Syndrome / Q000453:epidemiology; D042241:Early Diagnosis; D005260:Female; D005865:Gestational Age; D006801:Humans; D015160:Hydrops Fetalis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D018191:Lymphangioma, Cystic / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies; D014314:Trisomy; D000073842:Trisomy 18 Syndrome; D016216:Ultrasonography, Prenatal