title: Fetal nuchal translucency scan in Nigeria.
abstract: BACKGROUND
  To evaluate the performance of first trimester nuchal translucency scan screening among pregnant women in Nigeria.
  
  
  METHODS
  A prospective observational and questionnaire based study involving 510 pregnant women between 11(+0) and 13(+6) weeks. Routine counselling and nuchal translucency measurement was conducted using the FMF, London guidelines. Chorionic villous sampling was done at NT ≥ 2.5 mm or ≥ 95th centile.
  
  
  RESULTS
  Five hundred and ten out of 542 (94.1%) were analysed, mainly referred by health care workers (87.2%) and from predominantly private facilities (94.3%). The number of NT scans performed increased in successive years with corresponding decrease in the mean scanning time. Scan was successfully completed at first attempt in (96.5%), with mean scanning time of 28.3 minutes. Nuchal translucency increases with gestational but not maternal age. The median and 95th centile at 11(+0) week was 1.2mm and 1.7 mm and at 13(+6) weeks was 1.5 mm and 2.2 mm. Using a cut-off of ≥ 2.5 mm or ≥ 95th centile, 17 (3.3%) screened positive. Three out of the 17 had invasive testing and 2 (DR = 66.7%) were confirmed trisomy 21, with a false positive rate of 5.9%. Although majority (86.4%) were willing to have invasive testing, only few (3 or 17.6%) of the high risk group had testing.
  
  
  CONCLUSIONS
  The study demonstrated that NT scan is feasible as a screening tool in pregnancy in Nigeria. Measures of improving utilization include wider dissemination of information, provision of dedicated NT clinics and manpower training.
authors.affiliation: Fetal Medicine Unit, Olabisi Onabanjo University Teaching Hospital, Sagamu, Ogun State, Nigeria ; High Rocks Fetal Medicine and Genetic Diagnosis Centre, Oshodi, Lagos, Nigeria.
authors.forename: Olufemi Adebari
authors.initials: OA
authors.lastname: Oloyede
authors.affiliation: Whipps Cross University Hospital, London.
authors.forename: Mkpe
authors.initials: M
authors.lastname: Abbey
authors.affiliation: Manor Hospital, Walsall, United Kingdom.
authors.forename: Adeniyi Adebowale
authors.initials: AA
authors.lastname: Oloyede
authors.affiliation: High Rocks Fetal Medicine and Genetic Diagnosis Centre, Oshodi, Lagos, Nigeria.
authors.forename: Onyinye
authors.initials: O
authors.lastname: Nwachukwu
mesh_terms: D000328:Adult; D004314:Down Syndrome / Q000175:diagnosis*; D005189:False Positive Reactions; D005240:Feasibility Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D008875:Middle Aged; D009549:Nigeria; D048208:Nuchal Translucency Measurement / Q000379:methods*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods*; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Down syndrome; Nuchal translucency scan; Performance