Parents-to-be looking for keepsake images of their unborn babies have been warned about the possible health risks involved in unnecessary ultrasound scans.
The Health Protection Agency (HPA) warning came after its independent Advisory Group on Non-Ionising Radiation (AGNIR) said there had been unconfirmed reports suggesting possible effects of the scans on developing nervous systems.
However, the body was quick to reassure prospective parents that evidence did not suggest diagnostic ultrasound affected mortality of babies during pregnancy or soon after birth.
Scans to check the health of babies are important and safe, the HPA said. But it added that people should be aware of possible health risks of scans which do not have "a defined diagnostic benefit".
With widespread use of ultrasound and its growing commercial use for "souvenir" foetal imaging, and unconfirmed indications of neurological effects on the foetus, more research was needed to ascertain whether there were any long-term adverse effects of diagnostic ultrasound, said AGNIR chairman Professor Anthony Swerdlow.
There is a safe track record for diagnostic use of ultrasound but there are also uncertainties that need to be clarified, said HPA chief executive officer Justin McCracken.