ASSESSMENT OF GESTATIONAL AGE

COMPARISON BETWEEN TRANSCEREBELLAR DIAMETER VERSUS FEMUR LENGTH ON ULTRASOUND IN THIRD TRIMESTER OF PREGNANCY

Abstract

Objective: To compare correct assessment of gestational age between
Transcerebeller diameter versus femur length in third trimester (28-40) using first day of last
menstrual period for actual period of gestation. Study Design: Cross-sectional descriptive study.
Place and Duration of Study: Department of Obstetrics and Gynecology, Bahawal Victoria
Hospital, Bahawalpur from Jun 2012 to Dec 2012. Methodology: This study was performed on
327 patients in third trimester of pregnancy from 28-40 weeks fulfilling the inclusion criteria.
Ultrasound measurements of transcerebellar diameter (TCD) and femur (FL) were made with
commercially available real time ultrasound equipment Toshiba Nemio-10 model 2009,
Transducer frequency 50/60 Hz. Collected data was analyzed by SPSS version 10. Results: Out
of 327 patients, TCD was found to give correct assessment corresponding to the gestational age
by LMP in 262 (80.1%) patients, while in 232 (70.9%) patients FL was found to give correct
assessment corresponding to the gestational age by LMP. Conclusions: Transcerebellar
diameter is more reliable method of gestational age determination in third trimester of pregnancy
than femur length. TCD can be used as a tool to assist in the assessment of gestational age in
third trimester.