Transcerebellar diameter versus biparietal diameter for the measurement of gestational age in third trimester.

Aim: To compare the accuracy of biparietal diameter and transcerebellar diameter in measuring the gestational age during the third trimester of pregnancy.

Material And Methods: In this prospective observational study, 275 pregnant women with singleton pregnancy between 32 and 37 weeks gestational age were recruited from the outpatient clinics of both Helwan University Hospital and Ain Shams University Maternity Hospital, Cairo, Egypt, during the period from February 2021 to August 2021. Transcerebellar and biparietal diameters of the fetus were measured by a radiologist blinded to the women's gestational age, and compared to the gestational age acquired from a reliable date of first day of last menstrual period.