Understanding your Babies Ultrasound scan - part 2

Most parents look forward to their scan because it gives you the first glimpse of your baby. The person who carries out your scan (sonographer) will probably give you a printout of your baby as a keepsake. Abbreviated medical words such as BPD are often used to describe your babies growth and development. Here we provide you with an understanding of frequently used terms used on your ultrasound report.

Measurements and tests

• CRL
  Crown Rump Length. Top of head to end of bottom. Taken at 6 - 12weeks.
• BPD
  Bi Parietal Diameter. The width across the baby's head. Taken at 13 - 39 weeks.
• HC
  Head Circumference. The distance around the baby's head. Taken at 22 - 39 weeks
• AC
  Abdominal Circumference. The distance around the baby's tummy/belly. Taken at 22 - 39 weeks
• FL
  Femur length. The length of the thigh bone. Taken at 13 - 39 weeks
• EFW
  Estimated Fetal Weight. Calculated from the BPD;HC;AC;FL at growth scan. Gives actual weight at time of scan, not predicted birth weight.
• LV
  Liquor Volume. The amount of fluid surrounding the baby.
• LPD
  Liquor Pool Depth. The depth of a single pool of fluid.
• AFI
  Amniotic Fluid Index. A calculation intended to work out the overall amount of fluid (space) the baby has around it.
• Down's Screening
  A set of tests designed to work out the level of risk of having a baby with Down's Syndrome.
• Triple test
  The triple test assesses the risk of having a Down's baby based on maternal age and maternal serum markers (alpha feta protein, unconjugated oestriol and total human chorionic gonadotrophin). Serum is taken from 15-20 weeks gestation, ideally 16 weeks. A high hCG, low AFP and low oestriol suggest a Down's child. Results are expressed in terms of the risk of having a Down's child eg. 1 / 145.
• Nuchal Translucency Scan
  A scan done at 11 - 13 weeks gestation during which a measurement is taken of the fat pad at the back of the neck and the result is considered together with other factors e.g. mother's age, family history, to calculate an individual risk of having a baby with Down's Syndrome.
• Amniocentesis
  A small sample of the Amniotic fluid (liquor) is taken from around the baby to test for serious abnormalities.
• AFP
  Alpha-Feto-Protein. A chemical found in the blood of pregnant women the levels of which are raised in such cases as twin pregnancy, spina bifida etc.