A dating scan is an ultrasound scan to determine how many weeks pregnant you are and your due date. Read on for more information about what a dating scan offers.
A dating scan might be recommended to confirm your due date if you are unsure of your last menstrual period or your date of conception. Itís not compulsory, but you should discuss whether you want or need a dating scan with your doctor or midwife.
It is usually offered to pregnant women from 10 weeks to 13 weeks gestation, but can be carried out any time from 6 weeks. If you have had bleeding during your pregnancy or you have had previous miscarriages, your doctor or midwife may recommend an early dating scan from 6 to 10 weeks gestation.
If you choose to have a dating scan, it will most probably be your first scan. You will need to get a referral from
A dating scan is carried out by ultrasound. A sonographer, who is usually a radiographer or a midwife trained in ultrasound, will complete your scan.
If the scan is after 10 weeks, ultrasound recordings are usually made through your abdomen. The sonographer will put gel on your abdomen and move a hand-held device called a transducer, back and forward over your skin.
In some situations, such as when the scan is completed before 10 weeks of gestation or you are overweight, you may also need a vaginal scan. Your sonographer will let you know if this is needed.
Check with your ultrasound clinic for any preparation you need to do prior to the scan.
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.
The scan will take 5Ė10 minutes to perform.
During a scan the babyís size will be measured from head to bottom. 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.
At a dating scan you will also be able to: