It is now widely used and has become a useful tool in monitoring and diagnosis.
Ultrasound scans use sound waves which are safe for you and your baby.
The point of the scan is to work out how many weeks pregnant you are. Ectopic pregnancy and miscarriage: diagnosis and initial management CG 154.
You may have calculated the length of your pregnancy from the first day of your last menstrual period (LMP).
How big your baby will be depends on when you have the scan: After 13 weeks, your baby can curl up and stretch out, so measuring the length becomes less accurate.
Therefore, from 13 weeks, or if your baby is longer than 84mm, the circumference of the head becomes the best way to measure your baby. Evaluation of gestation emedicine.[Accessed July 2017] Newson L.
If you do know the conception date, this is counted as day 14, not day one.
If your cycle is irregular or you've recently been on the pill, working out the date from your LMP probably won't work. If the scan date differs from your period dates, the scan date will be used. It should be possible to discuss the findings with an obstetrician within 24 hours or soon after detection of the anomaly.This is a type of fetal assessment using specific criteria to reach a well-being score for high-risk pregnancies.The first ultrasound scan is usually performed before 15 weeks.Pregnancies affected by aneuploidy (abnormal chromosome number) will have sonographic markers.It is based on the Apgar scoring system used to assess the condition of the newborn.