For Brioney, the procedure was more straightforward and took about 20 minutes. She lay flat as a specially-designed machine fired high-powered ultrasound waves at tiny blood vessels in her placenta. “It was very quick and pretty painless,” she said.
Brioney and the other pregnant women, who were from the UK and across Europe, took part in the study after scans detected the condition during early pregnancy.
Prof Christoph Lees, head of fetal medicine at Imperial College Healthcare NHS Trust and professor of obstetrics at Imperial College London, said the research was “very promising”.
“If this could work in a fully-fledged study, it could give hope to a lot of women who otherwise might have to have quite invasive treatment,” he said.
Ultrasound is regularly used in medical scans to produce images of the body, and is known to be very safe – but this type of ultrasound is completely different and much more focused.
The heat created by its beams can seal blood vessels just 2mm in diameter, about 5-6cm below the skin.
The procedure blocked blood flow in 90% of the blood vessels treated as part of the study, and there were no unwanted side-effects.