ABSTRACT
To determine the ultrasonographic appearance and size of epiphyseal ossification centers of fetal peripheral long bones for assessment of third trimester gestational age. Descriptive, Observational study. This study was carried out at Department of Radiology, Dow University of Health Sciences/Civil Hospital Karachi, from February 2009 from July 2009. 200 pregnant females were examined having gestational age of 28 or more weeks. Obstetrical ultrasound was done using 3.5 MHz convex transducer on Toshiba ultrasound scanner model Nemio-17. Measurement of Biparietal Diameter, [BPD], femur Length [FL] and abdominal Circumference [AC], placental localization and assessment of liquor was done as per standard protocol. The distal femoral, proximal tibial and proximal humeral ossification centers were identified and measured. Gestational age correlated well with appearance and size of distal femoral, proximal tibial and the proximal humeral epiphyseal ossification centers but even better with the sum of the three ossification centers. Ultrasonographic visualization of the epiphyses ossification centers may be a useful marker of fetal gestational age