What does a pregnancy ultrasound scan show?

Pregnancy ultrasound scans: Most hospitals will offer women at least two ultrasound scans during their pregnancy. The first is usually around eight to 14 weeks and is sometimes called the dating scan because it can help to determine when the baby is due. The second scan usually takes place between 18 and 20 weeks and is called the anomaly scan because it checks for structural abnormalities.

Ultrasound scans use sound waves to build up a picture of your baby in your uterus. They are completely painless, have no known serious side effects on mothers or their babies, and may be carried out for medical need at any stage of pregnancy. If you have any concerns about having a scan, talk it over with your midwife, GP or obstetrician.

What does ultrasound scan show?   

• Check your baby’s measurements. This gives a better idea of when your baby was conceived and when it is likely to be born.

This can be useful if you are unsure about the date of your last period or if your menstrual cycle is long, short or irregular. Your due date may be adjusted depending on the ultrasound measurements.

• Check whether you are carrying more than one baby.

• Detect some abnormalities, particularly in your baby’s head or spine.

• Show the position of your baby and your placenta. Sometimes a caesarean section is recommended – for example if your placenta is low lying in late pregnancy.

• Check that your baby is growing and developing as expected (this is particularly important if you are carrying twins or more).