20 week scan - what does it test for?

[MrsCurly]

What does the 20 week scan actually test for? Is it just a general check-up or does it also look for specific problems that otherwise would be missed?

I've been told that my 12 week scan was very detailed and the kind of anomalies that 20 week scans look for would also have shown up at 12 weeks, so it is not really necessary. It is mostly done for reassurance.

Does this ring true?

It shows the baby is developing normally and that everything is where it should be - it's mostly measuring bone length compared to norms (short arms or legs can indicate a problem). Or brain related issues which don't show up earlier.

Mostly it is just to check the baby is still growing as it should be

it checks for quite a lot

npt everyone has a 12 week scan

you can see in more detail at a 20 week scan than you can at 12 weeks

they can also check the placental position

it is not just done for reassurance - it is actually called an anomaly scan

also, some hospitals will sex the baby at this time

they check baby is developing normally. so checking all arms, legs, fingers, toes, heart and brain, spine and skull

i found out at my 20 week scan that ds3 had enlarged ventricles of the brain, thankfully it wasn't anything to worry about but if they'd been much bigger we'd have needed further scans and he may have needed treatment at birth

i also know 2 people who had kidney probs picked up at the 20 week scan, which needed treating at birth

and a person whose GD was diagnosed mainly from the size of baby at her 20 week scan!

so, IMO it's well worth having

Thanks for the advice and esp for the link.

The consultant I saw at the hospital was pretty dismissive about the purpose of the 20 week scan, and left me with the strong impression it wasn't really necessary. Ditto the midwife I've asked.

I can't make up my mind whether to have it or not!

They check absolutely loads, basically all organs are looked at as thisisyesterday says, as well as limb length and other sizes which are plotted on a centile chart to give an idea of how big the baby is. At that stage this doesn't mean you can predict birth weight, but it might suggest a long baby for example.

We found out our 1st had a kidney problem that needed treatement and follow up.

Where I live the hospital sends out a detailed letter telling you what they look for, and also the likelihood of picking up various problems (e.g. they're pretty likely to detect neural tube defects, may spot a marker for Down's syndrome like cardiac abnormalities / short limbs etc) so worth asking your midwife if you will get something similar perhaps?

In summary, definitely not just for reassurance because even if they find a minor problem it is far from reassuring BUT if we hadn't known about our son's kidney problem he would have had an increased chances of infections after birth due to lack of treatment and could have ended up with long term damage.

Cross post MrsCurly I'm very surprised at your consultant and midwife, in lots of places they don't do a 12 week scan as the main purpose is dating, and only give a 20 week scan as it is generally considered to be a more useful way to use resources!

Here it is the other way round - dating scan but no 20 week scan. Unless I go private.

Not sure but my ds2 was born with a 2 vessel cord which was missed at the scan and he also only has 3 fingers on his left hand that was missed at the all my scans including a 4d one but i know people who have had things picked up in their scans, i guess we were unlucky, well not unlucky because he is fine

Ah, then I guess the consultant and midwife can't really say that the 20 week scan is essential can they

Well mine was pointless in that way but i guess they knew there was nothing very wrong with ds2.

It is a very important scan it is the earliest they can detect soft tissues defect. They should tell you things like "I can see the blader emptying or being full", can detect kidney anomalies....
But saying that I had my 12 weeks scan done in France this time around and was amazed as how detailled and long it was there compare with the UK.

dear mamaloco, did u pay for the scan in france. i m due for my 20 wk scan in july and am planning to go to france during that time i also got a European Health Insurance Card. do i have to pay for this scan in france? please guide.tnxxxx