Your sonographer will let you know if this is needed. For an abdominal dating ultrasound, you will need to have a full bladder. You may be asked to drink some water and not go to the toilet beforehand because a full bladder helps to push your womb up to give a better picture.

For a vaginal scan, you can have an empty bladder. This will provide a fairly accurate estimate of how many weeks pregnant you are. But it is important to remember that only a few women go into labour on their due date, so it can be more helpful to think about the month in which you are expecting your baby, rather than the exact day. Information on pregnancy ultrasound scans including when they are taken, what it can be used for, dating scans, anomaly scans, plus links to trusted resources.

This Dads Guide to Pregnancy article covers early pregnancy scans and screening, plus normal fetal development and early miscarriage for men, by men. In the second trimester of pregnancy, you may be offered to have an morphology scan anomaly scan. Learn about what it looks for and when it is performed. A nuchal translucency scan is part of the ultrasound scan that may give an indication of chromosomal abnormality.

Learn more about how and when it is performed. During your pregnancy, you will be offered a number of tests and scans. The aim is always to check on the health of you and your baby, but it can sometimes be overwhelming and confusing. Handy infographic that shows what you can expect at each antenatal appointment during your pregnancy. In the meantime, we will continue to update and add content to Pregnancy, Birth and Baby to meet your information needs.

Will the dating scan happen at exactly 12 weeks?

This information is for your general information and use only and is not intended to be used as medical advice and should not be used to diagnose, treat, cure or prevent any medical condition, nor should it be used for therapeutic purposes. The information is not a substitute for independent professional advice and should not be used as an alternative to professional health care. If screening tests show a lower risk, most parents choose not to put themselves, or their unborn baby through further, more invasive tests.

What do I need to know? Non-Invasive Prenatal Testing Nuchal Translucency Scan Pregnancy ultrasound scans Rhesus disease and Anti-D injections Testing and screening for chromosome abnormalities X-rays can affect your pregnancy What is a third trimester pregnancy growth scan?

What you need to know about a cervical length pregnancy scan 12 week pregnancy dating scan: Deciphering maternity note abbreviations.

Your maternity notes make for interesting reading. The sonographer will put ultrasound gel on your stomach to ensure good contact between your skin and the machine. They will then pass a probe over your skin.

This sends out ultrasound waves and picks them up again when they bounce back. A black and white picture of your baby will be shown on a small screen.

Having the scan does not hurt, but the sonographer may have to push quite firmly at times in order to see the deeper structures. Ultrasound scans are painless and non-invasive.

There are no known risks to the baby or the mother from having an ultrasound scan. However, ultrasound energy has the potential to produce biological effects on the body and therefore should be only be performed by appropriately trained healthcare providers for medical purposes see the table above.

Common conditions

Additional keepsake scans solely for the purpose of producing an image or video are not recommended. If you choose to have a scan, you also need to be prepared for the possibility that the information it reveals about your baby may not be reassuring. Making these decisions can be unsettling and challenging. The ultrasound scans you will be offered in your pregnancy are optional. You are well within your rights to decline any or all scans in pregnancy — or to agree to them all.