title: Sacrococcygeal teratoma: A population-based study of incidence and prenatal prognostic factors.
abstract: BACKGROUND
  Sacrococcygeal teratoma (SCT) is a rare congenital tumor associated with high rates of perinatal mortality and morbidity. This study evaluated the incidence, prenatal detection rate, and early predictors of a complicated outcome following diagnosis of SCT.
  
  
  METHODS
  We retrospectively identified all fetuses and newborns diagnosed with SCT in southern Sweden from 2000 to 2013. Prenatal sonograms, charts, and pathology reports were reviewed and analyzed. Each case of SCT was defined as complicated or uncomplicated based on the postnatal outcome. All cases with a fatal outcome or that required cardiac resuscitation during birth or surgery were classified as complicated.
  
  
  RESULTS
  The overall incidence of SCT was 1:13,982 (19 children in a cohort of 265,658 live births). A prenatal diagnosis was made in 74% of cases, there were no stillbirths or intrauterine deaths, and the overall mortality rate was 11%. Four cases of SCT (21%) were classified as complicated, and these cases had a significantly larger tumor size at gestational week 20 (P=0.048), had a significantly higher tumor growth rate (P=0.003), and were more often associated with polyhydramnios (P=0.01), and mainly solid/mixed morphology (P=0.001).
  
  
  CONCLUSIONS
  The incidence of SCT in southern Sweden was higher than those reported in most previous studies; however, the associated mortality rate was relatively low. Fetuses with large tumors, rapidly growing tumors, and polyhydramnios were more likely to experience a complicated outcome during the postnatal period.
authors.affiliation: Department of Pediatric Surgery, Skåne University Hospital, 221 85 Lund, Sweden; Department of Clinical Sciences Lund, Lund University, Box 117, 221 00 Lund, Sweden. Electronic address: mette.hambraeus@live.dk.
authors.forename: Mette
authors.initials: M
authors.lastname: Hambraeus
authors.affiliation: Department of Pediatric Surgery, Skåne University Hospital, 221 85 Lund, Sweden; Department of Clinical Sciences Lund, Lund University, Box 117, 221 00 Lund, Sweden.
authors.forename: Einar
authors.initials: E
authors.lastname: Arnbjörnsson
authors.affiliation: Department of Pediatric Surgery, Skåne University Hospital, 221 85 Lund, Sweden; Department of Clinical Sciences Lund, Lund University, Box 117, 221 00 Lund, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Börjesson
authors.affiliation: Department of Clinical Sciences Lund, Lund University, Box 117, 221 00 Lund, Sweden; Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Kjell
authors.initials: K
authors.lastname: Salvesen
authors.affiliation: Department of Pediatric Surgery, Skåne University Hospital, 221 85 Lund, Sweden; Department of Clinical Sciences Lund, Lund University, Box 117, 221 00 Lund, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Hagander
mesh_terms: D002675:Child, Preschool; D003050:Coccyx; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011379:Prognosis; D012189:Retrospective Studies; D012445:Sacrococcygeal Region; D013125:Spinal Neoplasms / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery; D013548:Sweden / Q000453:epidemiology; D013724:Teratoma / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery; D016216:Ultrasonography, Prenatal
keywords: Growth rate; Outcome; Polyhydramnios; Prenatal; Sacrococcygeal teratoma; Tumor size