Scans are part of you regular antenatal checks during pregnancy. Most pregnant women in the UK can expect to have only two scans, one at around 12 weeks and the other at around 20 weeks. Special or extra scans may be needed at other times during the pregnancy, particularly if there are pregnancy complications or the pregnancy is multiple. Scans are usually enjoyable and rewarding for prospective parents, giving them a chance to see their developing baby in the womb. But scans can also be worrying if you are not sure what to expect. Here we explain what to expect during your first scan and what information you will find out.


When does my first scan happen?

The first scan, called the dating scan, is usually at around 8-14 weeks and helps to determine when the baby is due.

A full bladder pushes your womb up and this gives a better picture, so you will probably be asked to drink a lot of fluid before the scan. The instrument that is passed backwards and forwards over your skin sends a high-frequency sound through your abdomen into the womb. The picture you will see on the screen is created by the sound that is reflected back. You will see an image of your baby. If the image seems confusing then ask for it to be explained. If you would like to take a picture home then ask for a copy of the picture.

What will I find out at my first scan?

  • The scan will check your baby's measurements. The measurements give a better idea of how many weeks pregnant you are. This can be useful if you're unsure about the date of your last period or if your menstrual cycle is long, short or irregular. Your due date is likely to be adjusted according to the ultrasound measurements.
  • The scan checks whether you're carrying more than one baby.
  • The scan detects some abnormalities, particularly in your baby's head or spine.
  • You are able to see the position of your baby and the placenta. This is important in some instances for example, when the placenta is low down in late pregnancy, special care may be needed at delivery, or a caesarean section may be advised.
  • The growth and development of your baby can also be checked. This is particularly important if you're carrying twins or multiple babies.

What won’t I find out at my first scan?

There are a few things that the first scan will not be able to show you and that can be checked at later scans.

Although the first scan detects some abnormalities it cannot check your baby in detail so around 18 to 20 weeks the second scan usually takes place. This is called the anomaly scan because it checks for structural abnormalities in the baby. This takes a closer look at your baby and placenta in detail and its main purpose is to check that your baby is developing normally.

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By 20 weeks, it's often possible to tell whether your baby is a boy or a girl. If you would like to know the sex of your baby ask your midwife whether it is your hospital’s policy to disclose this as some hospitals will not tell you.

What if I feel apprehensive?

Most parents look forward to their scan because it gives them a first glimpse of their baby. But, if you do feel apprehensive about your scan, remember that the scan is a positive thing as its purpose is to check that your baby is developing as he or she should.

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