I read the study in the Telegraph and wasn't convinced - I'll try and post it later if I can find it again - tbh, giving rats doses of anything, drugs or U/Ss, that would be huge even in humans then analysing the effects doesn't mean that (a) small human doses will do the same or even (b) rat and human morphology are similar enough for a similar thing to happen. One friend had 2 high-risk pregnancies and had lots of scans and her girls are fine, although I'm happy just to have 3 scans (dating, NT scan and abnormality scan).