BBC News investigation has uncovered failures in the diagnosis of serious medical issues during private baby scans.
More than 200 studios across the UK now sell ultrasound scans, with hundreds of thousands being carried out each year.
But the BBC has found evidence of women not being told about serious conditions and abnormalities.
The Care Quality Commission says there is good quality care in the industry but it has a "growing concern".
Private baby scanning studios offer a variety of services.
Some diagnose medical issues while others market themselves as providers of souvenir images or video of the ultrasound. Most sell packages providing a "reassurance scan" to expectant mums.
Many women BBC News spoke to said they had positive experiences at private studios, but we have also learned of instances where women said they were failed.
Charlotte, from Manchester, attended a scan in Salford with one of the biggest franchises, Window to the Womb, to record her baby's sex for a party and check its wellbeing.
BBC News has learned the sonographer identified a serious abnormality that meant the baby could not survive, where part or all of its head is missing, called anencephaly.
But rather than refer her immediately to hospital and provide a medical report, Charlotte was told the baby's head could not be fully seen and recommended to book an NHS anomaly scan.
She was also given a gender reveal cannon and a teddy bear containing a recording of its heartbeat as a present for her daughter.
"I was distraught," Charlotte said. "You've bonded with that baby."
"It's like a deep cut feeling," she added. "All of it could have just been avoided, we could have processed the news all together as a family because I was with my mum and dad, I would have had the support there."
Source: BBC News, 18 November 2020