Comparative Study between the Accuracy of Transcerebellar Diameter versus Femur Length and Biparietal Diameter Measurements in Estimation of Gestational Age during Third Trimester

Abstract Background Knowledge of accurate gestational age is of great importance in obstetric practice. Pregnancy complications as low birth weight, preterm labor are very common in pregnancies with unknown and inaccurate estimated gestational age, gestational age estimation is essential for proper prenatal care and determining whether the fetal size is appropriate-for- gestational age. Moreover, it is essential for many prenatal interventions, such as fetal lung maturation, use of magnesium for neuroprophylaxis in preterm infants, induction of delivery and neonatal resuscitation. Optimal assessment requires good judgment by the obstetrician caring for the patient. Objective To compare the accuracy of transcerebellar diameter versus the current fetal biometrics including (femur length and biparietal diameter) in estimation of the gestational age during the third trimester according to last menstrual period. Patients and Methods The study was conducted in clinic of Obstetrics and Gynaecology Department- MUST University Hospital. This study included 120 pregnant females. They were divided equally into three equal groups each contained 40 patients; Group I: Biparietal diameter measured group, Group II: Femur Length measured group, and Group III: Transcerebellar measured group. Results The comparison in 1 week proved that the TCD gave correct assessment of gestational age in 107 patients (89.17%), the BPD gave correct assessment of gestational age in 73 patients (60.83%) and the FL gave correct assessment of gestational age in 97 patients (80.83%). Conclusion Transcerebellar diameter is the most accurate and reliable method for assessment of gestational age in third trimester followed by FL and the least accurate is the BPD.