Which of the following parameter gives accurate assessment of Gestational Age?

Best parameters for estimation of fetal age FIRST TRIMESTER : CROWN RUMP LENGTH SECOND TRIMESTER : BIPARIETAL DIAMETER THIRD TRIMESTER : FEMUR LENGTH OVERALL : CROWN RUMP LENGTH BPD is measured in the trans thalamic view at the level of the thalami and cavum septum pellucidum. Cephalic index = BPD divided by occipito frontal diameter (OFD) CI = BPD/ OFD. If head shape is flattened (dolichocephaly) or rounded (brachycephaly), then HC is more reliable than BPD. USG in Pregnancy Best time to assess gestational age by USG is 9-12 weeks (by Crown rump length). Best indicator of fetal growth - Abdominal circumference. So the best USG parameter to detect IUGR is Abdominal circumference. The best USG parameter to detect Macrosomia is Abdominal circumference.