Accuracy of pregnancy dating scans
The dating scan and anomaly scan are offered to all women, but you don't have to accept them.
Your choice will be respected if you decide not to have the scans, and your antenatal care will continue as normal.
The second scan offered to all pregnant women is called the anomaly scan, or mid-pregnancy scan, and usually takes place between 18 and 21 weeks of pregnancy.
This scan checks for structural abnormalities (anomalies) in the baby.
It's very exciting to "see" your baby in the womb, often moving their hands and legs.
If it's difficult to get a good image, the scan may take longer or have to be repeated at another time.
Ultrasound scans use sound waves to build a picture of the baby in the womb.
The scans are painless, have no known side effects on mothers or babies, and can be carried out at any stage of pregnancy.
Ultrasound scans can sometimes find problems with the baby.
Most scans show that the baby is developing normally and no problems are found.If you're offered further tests, you will be given more information about them so you can decide whether or not you want to have them.