title: Ultrasound estimation of foetal gestational age by transcerebellar diameter in healthy pregnant nigerian women.
abstract: BACKGROUND
  Ultrasonography has application in advanced obstetric practice through relatively detailed assessment of foetal anatomy and accurate assessment of gestational age (GA), especially during the first half of pregnancy. Foetal trans-cerebellar diameter (TCD) is an emerging parameter for gestational age determination among Africans.
  
  
  OBJECTIVE
  This study was carried out to establish baseline data for TCD at various corresponding gestational ages in Nigerian women, and evaluate the correlation between these two parameters.
  
  
  METHODS
  Four hundred and fifty healthy singleton pregnant women, referred for antenatal scans were prospectively studied, following informed consent. Main inclusion criterion was certain last menstrual dates. A SONOACE χ⁶ ultrasound scanner, with a curvilinear probe and 3.5 MHz transducer, was used to measure the TCD. Data analysis was done and statistical significance set at p ≤ 0.05.
  
  
  RESULTS
  TCD of the foetuses studied ranged from 11.9 mm (at 13 weeks) to 59.3mm (at 41 weeks) with a mean value 34.2 ± 14.1mm.There was significant correlation between TCD and menstrual gestational age (r =0.984; p=0.000). TCD has a predictive accuracy of 96.9% with a standard error of ± 10 days.
  
  
  CONCLUSIONS
  A normogram of foetal TCD throughout gestation is established for Nigerian Africans.
authors.affiliation: Department of Radiology, University of Benin Teaching Hospital PMB 1111, Benin-City, Nigeria.
authors.forename: M O
authors.initials: MO
authors.lastname: Orji
authors.forename: A A
authors.initials: AA
authors.lastname: Adeyekun
mesh_terms: D000293:Adolescent; D000328:Adult; D044383:Black People; D002508:Cephalometry; D002531:Cerebellum / Q000000981:diagnostic imaging* / Q000196:embryology*; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D008875:Middle Aged; D009549:Nigeria; D009929:Organ Size; D011237:Predictive Value of Tests; D011247:Pregnancy; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal; D055815:Young Adult