Ultrasound scanning is generally considered to be a safe procedure for monitoring the health of unborn babies. However, research published recently in the journal Epidemiology casts doubt on this assumption by hinting that ultrasound might affect brain development.

The study, from the Karolinska Institute, indicated that boys who are scanned in the womb are significantly more likely to be left handed than those who are not scanned. This might not sound like a big handicap in itself, and the Independent's (UK, 10 December) assertion that left handedness is “recognized as a mild form of brain damage” is sure to offend many left-handed people. However, the switch in handedness could indicate more serious problems. As the Sunday Telegraph (UK, 9 December) points out, “these people face a higher risk of conditions ranging from learning difficulties to epilepsy”, although it is worth mentioning that no such adverse effects have yet been reported.

So, should expectant mothers think twice before having a scan? Maternity service campaigner Beverly Beech thinks so: “I am not sure that all the benefits of ultrasound scans outweigh the downsides. We should be advising women to think very, very carefully before they have scans” (Sunday Telegraph). The researchers, on the other hand, were keen to play down the risks. One team member, Juni Palmgren, said “I would urge people not to refuse ultrasound scanning as the risk of brain damage is only a possibility — but this is an interesting finding and needs to be taken seriously” (BBC News, 9 December).

Not everyone was pessimistic however. The web site Anything Left-Handed commented “if having ultrasound tests encourages left-handedness, that seems to us to be a GOOD THING!”