• Normal Anatomy at 18-22 weeks slide show

• Amniotic Fluid Index

• Cervix

• Doppler Techniques

Normal biometric calculations

Charts and Tables

• Gestational sac size
• Crown rump length

• Biparietal Diameter

• Head Circumference

• Head circumference 5th and 95th centiles

• Abdominal Circumference

• Femur (includes interactive charts)

• Fetal Weight

• BPD, FL, tibia, fibula, humerus, radius

• Humerus

• Tibia

• Fibula

• Radius

• Ulna

• Foot

• Clavicle (includes interactive charts)

• Transverse cerebellar diameter (includes interactive charts)

• Thoracic Circumference

• Renal Volume

• Binocular distance

• Interocular distance

• Ocular Diameter

• Ear Length

• Nuchal Thickness

• Nuchal translucency

• Fetal Length from femur length