title: Sonographic Biometry of Fetal Interorbital Distance as a Predictor of Gestational Age in Enugu, Southeast Nigeria.
abstract: OBJECTIVE
  The objective of this study was to develop a sonographic technique for the measurement of fetal interorbital distance (IOD) for gestational age (GA) determination and to establish a normogram of IOD for the local population.
  
  
  METHODS
  The fronto-transverse sonographic technique was established as a feasible and reproducible technique for IOD measurement. Two independent and experienced sonographers tested the technique and had a coefficient of variation of 17.64% and 19.72%, respectively, which is statistically insignificant. The established technique was used to measure the IOD of 320 fetuses from the 13thweek to 40thweek GA, while standard technique was used to measure biparietal diameter (BPD), head circumference (HC) and femur length (FL) of the fetuses. The data obtained were used to determine the regression equation GA = 6.24 + 4.89 IOD for the prediction of the gestational age.
  
  
  RESULTS
  There was good correlation between IOD, BPD, HC and FL. The predicted normogram of IOD was compared with normogram of the Caucasian population. The result showed that there was no statistical difference between them (p < 0.05).
  
  
  CONCLUSIONS
  Results from the study suggest that the fronto-transverse technique is a feasible and reproducible technique for IOD measurement and the established normogram of IOD can be a veritable statistic for GA prediction in our locality.
authors.affiliation: Department of Medical Radiography and Radiological Sciences, Faculty of Health Sciences and Technology, University of Nigeria, Enugu, Nigeria. E-mail: uinwadike@yahoo.com.
authors.forename: U I
authors.initials: UI
authors.lastname: Nwadike
authors.affiliation: Department of Medical Radiography and Radiological Sciences, Faculty of Health Sciences and Technology, University of Nigeria, Enugu, Nigeria.
authors.forename: K K
authors.initials: KK
authors.lastname: Agwu
authors.affiliation: Department of Medical Radiography and Radiological Sciences, Faculty of Health Sciences and Technology, University of Nigeria, Enugu, Nigeria.
authors.forename: C U
authors.initials: CU
authors.lastname: Eze
authors.affiliation: Department of Radiology, Faculty of Medical Sciences, Nnamdi Azikiwe University, Nrewi, Anambra, Nigeria.
authors.forename: O C
authors.initials: OC
authors.lastname: Okpala
authors.affiliation: Department of Paediation Medicine, Faculty of Medical Sciences, University of Nigeria, Enugu, Nigeria.
authors.forename: A O
authors.initials: AO
authors.lastname: Onu
keywords: Fetal interorbital distance; Nigeria; fronto-transverse technique; gestational age; normogram