title: Comparison between transcerebellar diameter with biparietal diameter of ultrasound for gestational age measurement in third trimester of pregnancy.
abstract: OBJECTIVE
  To determine the frequency of correct assessment by transcerebeller diameter (TCD) versus biparietal diameter (BPD) for gestational age measurement at 36 weeks of pregnancy using first day of last menstrual period (LMP) for actual period of gestation.
  
  
  METHODS
  Quasi experimental.
  
  
  METHODS
  Department of Obstetrics and Gynaecology, Bahawal Victoria Hospital, Bahawalpur from May to November 2010.
  
  
  METHODS
  This study was performed on 228 patients at 36 weeks of pregnancy fulfilling the inclusion criteria. Ultrasound measurements of TCD and BPD was made and compared with LMP. Collected data was analyzed by SPSS version 10. Proportoin of correct diagnosis by each measurement was determined and compared using chi-square test with significance at p < 0.05.
  
  
  RESULTS
  Out of 228 patients, TCD was found to give correct assessment in 209 patients (91.7%; p = 0.001) corresponding to the gestational age by LMP i.e 36 weeks. BPD was found to give correct assessment corresponding to the gestational age by LMP in 176 patients (77.2%).
  
  
  CONCLUSIONS
  Although both BPD and TCD are accurate biometric parameters at 36 weeks of gestation, transcerebellar diameter is more reliable method of gestational age determination in third trimester of pregnancy than biparietal diameter. TCD can be used as a tool to assist in the assessment of gestational age in third trimester.
authors.affiliation: Department of Obstetrics and Gynaecology, Bahawal Victoria Hospital, Bahawalpur. adilgemini@gmail.com
authors.forename: Faiza
authors.initials: F
authors.lastname: Naseem
authors.forename: Naheed
authors.initials: N
authors.lastname: Fatima
authors.forename: Shakeela
authors.initials: S
authors.lastname: Yasmeen
authors.forename: Saima
authors.initials: S
authors.lastname: Saleem
mesh_terms: D000328:Adult; D002508:Cephalometry / Q000379:methods*; D002531:Cerebellum / Q000000981:diagnostic imaging* / Q000254:growth & development*; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012016:Reference Values; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal