The fetal transverse cerebellar diameter/abdominal circumference ratio: a gestational age-independent method of assessing fetal size.

The relationship between the fetal TCD and the AC throughout pregnancy was investigated in a prospective, cross-sectional study of 700 well dated, normal pregnancies between 14 and 42 weeks of gestation and tested in 30 known SGA infants. Fetal measurements included the TCD, AC, BPD, HC, and FL. The TCD/AC ratio was calculated for each patient. Statistical analysis using linear regression and Student's t-test was performed. Strong correlation existed between gestational age and transcerebellar diameter (R 2 =0.9464), between gestational age and AC (R 2 =0.9685), and between TCD and AC (R 2 =0.9561)