Too many ultrasounds unsafe?

Ultrasound is generally considered safe throughout pregnancy. This does depend somewhat on the competence of the staff and the correct use of equipment- anyone can buy an ultrasound machine and set themselves up as a sonographer so do check details carefully of any private clinic. https://www.sor.org/getmedia/68635988-565a-45a8-8b57-53b29e8f651d/Competencies-for-ultrasound-practice-in-private-baby-scan-clinics_V2_D1-3

Ah, crossposted - thanks!

That seems to be correlation rather than cause. I'm interested in this subject, could you share any studies which show a causal link please?

Just for context a couple of studies are here
https://pubmed.ncbi.nlm.nih.gov/8105165/
https://pubmed.ncbi.nlm.nih.gov/15582061/

But you are all citing scanning for medical purposes. My understanding of the OP is that the previous scans have all been private "reassurance" scans rather than medically necessary ones. As the risk of IUGR outweighs the benefit of reassurance scans, it would be recommended not to have any more. Of course she should have any medically necessary scans that are recommended, but no more reasssurance scans....

As the mother of a baby born with complex medical needs and the mother of identical healthy twins, who had scans for both pregnancies at 7, 12, 15, 20 weeks and then every few weeks from then until birth at 35 and 36 weeks, the scans have had zero impact on them.

However what constant scanning can affect is your mental health. If you have a scan at 20 weeks, get the all clear but start convincing yourself you need to have one more in a few weeks then one more in a few weeks and then one more.... you're gonna make yourself ill.

Perhaps see when they advise for latest scans (private places don't tend to go really late as you can't see much) and aim for one then, or around 30 weeks so halfway. They're also not cheap, money better spent on the baby x

They aren't harmful, but I think you need to put in context what you think they are telling you. To have had 4 at 18 weeks in the early stages is a lot- what are you looking for? The scan tells you they have a heartbeat at that moment.but can't tell you they will be ok the day or week after. There's nothing to be done regardless. More scans won't change the outcome if otherwise everything is as normal.
Ones in the latter stages for growth and liquor make a bit more sense.

I had to have a scan every week when I was pregnant with my daughter who’s now a very healthy 14 year old. Try not to worry.

But you’re more likely to have a lower birth weight not because of all the scans but because of another reason which is why you’d have all the scans. My high risk twin pregnancy included fortnightly scans throughout.

There's no evidence (that I've seen) that ultrasound is unsafe, in fact, it is used therapeutically to treat some medical conditions, for example, musculoskeletal issues!

There is some evidence that intensive scanning may be linked to IUGR (Intra-Uterine Growth Restriction) and lower birthweight. There is a separate issue about what (I'm assuming, as you've not mentioned medical concerns) private scans will tell you and support you in terms of if an issue with the pregnancy is discovered. Personally, if I were you I wouldn't have any more private scans and just have your remaining NHS scan and any additional scanning that might be recommended by your medical team if necessary.

It's extremely unlikely there will be any effects of additional scans, but there is a risk and the gain probably isn't worth the risk being taken.

I think most places (private scans) will ask you to space them two weeks apart but I’m not sure if that’s a safety concern or not. I think that’s a question for the midwife

Not unsafe