A short summary, a sentence or two. May be left blank.
Required. An illustrative image for the article. Recommended size is 1242 x 1700. Insert the image directly - do not include any other text or HTML.
CURRENTLY NOT USED. A thumbnail image for the article. Minimum recommended size is 200px by 125px and the recommended
aspect ratio is 1.6 width to 1 height. Insert the image directly - do not include any other text or HTML. May be left blank.
The 20-week scan - also known as the mid-pregnancy ultrasound or the anomaly scan - should be done between 18 and 20 weeks, plus six days gestation.
This is the scan that lots of women get really excited about, since it’s the first time they will see something that vaguely resembles a baby. If he or she isn't demurely crossing their legs, you might be given the option of finding out the sex, too.
What happens during the scan?
It's exactly the same format as the 12-week-scan so it's the same drill for you: full bladder before the scan, crossed legs while you wait, gel on belly, picture of baby on screen.
The image of your baby is much more detailed than your 12-week scan and it can be a mind-blowing experience. The scan might take a bit longer than your last, though - the sonographer has to have a really detailed look at the development of your baby, and the health and position of your placenta.
The anomaly scan checks your baby for structural abnormalities. It can pick up serious problems, so this is something to bear in mind if you're deciding whether to take someone with you.
Required. Do not embed images in the body
What does the scan show?
The sonographer will check your baby's head, face and spine and see whether all the bones align.
All internal organs will be checked to see they have developed properly. The heart is checked to ensure the four chambers are of equal size and the valves appear to be working with every heartbeat.
Your baby's kidneys and stomach will be checked to see if they're functioning properly, and limbs, hands and feet will also be examined.
The position of the placenta will be noted; if it is lying low in your uterus, you'll need to have another scan later on.
The sonographer will also check the umbilical cord and the volume of amniotic fluid surrounding your baby.
There will be various measurements made during the scan, primarily head circumference; abdominal circumference and thigh bone length. These measurements indicate whether your baby is developing as expected and act as a double-check on your estimated due date.
As well as developmental checks, the sonographer is looking for specific conditions that may be treatable, or may jeopardise your baby's survival. These are:
Anencephaly (a brain disorder)
Serious cardiac abnormalities
Bilateral renal agenesis (where the kidneys fail to develop)
Lethal skeletal dysplasia (where the skeleton does not develop as it should)
Edwards' syndrome (Trisomy 18)
Patau's syndrome (Trisomy 13)
If the sonographer detects any problems, you will be referred to a fetal medicine specialist and should be seen within a few days. You will be examined again and it may be that your baby can be treated within the womb or that they will need treatment after their birth. You will also be offered counselling and support if you need it.
May be left blank, if body is long and there is a natural break to have quotes appear use this secondary body. Do not embed images in the body
A talk URL related to this article. This should just be the URL; not a link.
Talk Link Text
Mumsnetters discuss antenatal scans
The text for the link to a talk thread. This should just be the text of the link; not a URL which should instead be entered above.
This is used to encourage users to capture something in their journal. For example, "Take a picture!"