Just how safe really is it for pregnant women to opt for multiple scans?
One of the most exciting things after finding out that you're pregnant is going for a scan and seeing your baby for the first time.
But many parents-to-be aren't satisfied with just the standard two NHS scans usually carried out at 12 and 20 weeks and they're paying to have more - sometimes a lot more.
Are multiple scans doing more harm than good?
In the UK, research by parenting site ChannelMum.com suggests almost one-third of pregnant women pay for private scans as well as having the routine NHS ultrasounds, and while 20% of those who have extra scans fork out for two, 18pc pay for at least three, and one in 50 have nine or 10 extra scans.
As well as the expense, the trend has raised fears that too many high-intensity scans may actually pose a threat to the foetus.
While the recommended amount of scans is completely safe, some experts say it's unclear what the effect of prolonged and frequent scans may be on unborn babies, particularly if the sonographer is untrained.
ChannelMum says some clinics offer scans of longer than 30 minutes, against medical advice, while others use unregistered sonographers who are unable to provide diagnoses or support if a problem is detected.
Mervi Jokinen, practice and standards adviser at the Royal College of Midwives (RCM), points out that the National Institute For Health and Care Excellence (NICE) advises that pregnant women have an early scan, and then a screening scan for anomalies at around 18-20 weeks - and the advice takes into account all the known potential harms and benefits of the procedure.
"Any further scans beyond these recommendations should be clinically indicated and based on the needs of the women and her developing baby," she stresses.
ChannelMum founder Siobhan Freegard, says: "Having a scan can be a wonderful way to bond with your baby and provide reassurance when you're worried.
"But we need to remember it's a medical procedure and should be treated very seriously. Clinics which allow multiple repeat scans without a medical reason could be risking the baby's health."
Is this 'scanxiety'?
The research found more than one-third of mums who've had extra scans did so because they felt anxious about their baby, leading experts to dub the phenomenon 'scanxiety'.
A further third just wanted to check on their baby without a medical reason, although most mums who paid for additional private scans (47%) did so out of concern for looking after their baby's health.
Of these, 27% checked if the pregnancy was viable, 12% ensured that there were no abnormalities earlier than the NHS scan, and one in 10 had bled or felt the baby's movement change, prompting them to get a scan.
Another 30% had a scan so they could discover their child's gender early, while 15% just wanted to show their baby to friends and family.
The study found 18% of pregnant mums paying for scans opted for normal 2D scans, while one in 10 paid for 3D or 4D scans, which create a lifelike picture showing the baby's features. A further 17% had a video made of their unborn child, and 1% even had a model made.
The RCM says that women needing extra assurance through additional scans is concerning.
"This type of reassurance and support is, and can, be provided by their midwife," Jokinen points out.
"Anxieties caused by reliance on technology can have an impact on a woman's pregnancy, causing undue stress and anxiety."
To help reassure expectant mothers who want to discover what their baby looks like during each week of their pregnancy, ChannelMum has launched a Pregnancy Week by Week section on their website, which shows pregnancy videos - including real scan footage.