title: A review of pregnancies complicated by congenital sacrococcygeal teratoma in the West Midlands region over an 18-year period: population-based, cohort study.
abstract: OBJECTIVE
  To describe the epidemiology and outcomes of sacrococcygeal teratoma (SCT) and identify the factors affecting prognosis in a population-based cohort.
  
  
  METHODS
  Analyses of fetal SCTs from a population-based congenital anomaly register between 1995 and 2012, linked to regional datasets. A systematic literature review was performed for published studies on perinatal SCT (1995 to 2012).
  
  
  RESULTS
  Thirty-six confirmed SCT cases were identified, giving a total prevalence of 0.30 per 10 000 births (95%CI 0.20-0.39). Twenty-three cases (63.9%) were diagnosed prenatally. There were six false positive prenatal diagnoses, and the positive predictive value of ultrasound for SCT was 79.3%. Secondary complications in prenatally diagnosed cases were polyhydramnios (27.2%), fetal hydrops (9.1%) and rapidly growing tumour (54.0%). The perinatal (PNMR) and infant mortality rates were 333.3 per 1000 births and 285.7 per 1000 live births, respectively. All stillbirths and infant deaths occurred in cases diagnosed prenatally. Factors associated with higher PNMR in registerable births were solid, vascular tumour composition (1000), polyhydramnios (667), premature delivery (667) and rapidly growing tumour (454). In the systematic review, prenatal hydrops fetalis and prematurity were the most morbid association in SCT.
  
  
  CONCLUSIONS
  Prenatal ultrasound was relatively sensitive and specific in diagnosing SCT with good survival rates in live-born cases.
authors.affiliation: The Fetal Medicine Centre, Birmingham Women's Foundation Trust, Birmingham, UK.
authors.forename: Amal
authors.initials: A
authors.lastname: Ayed
authors.affiliation: West Midlands Congenital Anomaly Register, Public Health England, Birmingham, UK.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Tonks
authors.affiliation: Birmingham Children's Foundation Trust, Birmingham, UK.
authors.forename: Anthony
authors.initials: A
authors.lastname: Lander
authors.affiliation: The Fetal Medicine Centre, Birmingham Women's Foundation Trust, Birmingham, UK.|Centre for Women's and Children's Health, Section Theme of Reproduction and Development, Institute of Metabolism & Allied Health Science, College of Medical and Dental Sciences, Birmingham, UK.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Kilby
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D015160:Hydrops Fetalis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D007231:Infant, Newborn; D007234:Infant, Premature; D054238:Perinatal Mortality; D006831:Polyhydramnios / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D015995:Prevalence; D012189:Retrospective Studies; D012445:Sacrococcygeal Region; D012680:Sensitivity and Specificity; D050497:Stillbirth / Q000453:epidemiology*; D013724:Teratoma / Q000151:congenital / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000401:mortality; D016216:Ultrasonography, Prenatal