Fetal biometry is one of the main reasons for performing obstetric ultrasound and therefore it is essential that all fetal measurements be performed correctly so as to ensure that antenatal decisions are appropriate.

A dating scan in the early first trimester measures the gestational sac or crown rump and the nuchal translucency assessment should also measure head, abdomen and limbs. The morphology ultrasound at 18 to 22 weeks must accurately measure all fetal parameters, with any deviations from the earlier scans being questioned. Correct measuring of fetal parameters in the third trimester for fetal growth/size is critical as results may be used to decide on timing for interventions such as induction of labour or caesarean section.

This workshop aims to reinforce the correct measuring procedures at all stages of pregnancy. Hands on scanning will be available for any participant. Fetal parameters to be reviewed include:
1. gestational sac
2. crown rump length
3. head circumference, biparietal diameter, occipito-frontal diameter
4. abdominal circumference - both trace and ellipse
5. femur, humerus and other long bones

Fetal weight formulas, amniotic fluid volume and cervical length will also be discussed.