They have become a must-have for excited parents-to-be, with their amazingly detailed depiction of unborn babies in three-dimensional realism.
But souvenir ultrasound scans offering parents keepsake pictures of their child in the womb could pose neurological risks, experts warned yesterday.
While ultrasound scans to check the child's health were deemed justifiable, the Health Protection Agency (HPA) expressed concern over the rise of so-called "souvenir scanning", when parents conduct ultrasound scans purely for the purpose of photographic mementos.
The tentative warning was issued in the wake of unconfirmed reports which suggested that such scans could pose neurological risks to unborn babies, as the beam of the ultrasound remains static over the head of the baby for a longer period than normal in order to get a sharp image.
Until recently, scans of unborn children were used solely by doctors to diagnose foetal abnormalities. But baby scanning is rapidly moving into the commercial sector, with parents-to-be willing to pay up to £250 for images of their unborn children. According to the sales pitches of growing numbers of non-diagnostic scanning clinics, such scans can help parents, friends and family "bond" with their unborn baby. The private scanning company www.beforethestork.co.uk claims on its website to offer parents "a chance to meet their unborn child for the first time without the distractions and time restrictions of a busy antenatal clinic".
An independent advisory group agreed that more research was required to determine the full extent of the problem and that, as of yet, there was not enough evidence to make an official judgement.
Nonetheless, the warning resonated among other experts. The British Medical Ultrasound Society agreed with the HPA's findings, advising parents against seeking scans that were solely for the purpose of a "nice snapshot for the baby book".
In a tentative conclusion, Anthony Swerdlow, the chairman of the report, stressed that the ultrasound has been used for 50 years without specific evidence of hazards. But he added: "In the light of the widespread use of ultrasound in medical practice, its increasing commercial use for 'souvenir' foetal imaging, and the unconfirmed indications of possible neurological effects on the foetus, there is a need for further research on whether there are any long-term adverse effects of diagnostic ultrasound."
Justin McCracken, of the HPA, added: "Overall, there is a track record of safety with diagnostic use of ultrasound, so people should continue using ultrasound for medical purposes. However, there are some uncertainties that need to be clarified through additional research."