The singer was previously diagnosed with twin-to-twin transfusion syndrome, which can put one or both babies at risk. And in March, Nelson underwent emergency surgery in a bid to save her children.
She wrote on Instagram at the time: “Unfortunately, the symptoms have got worse so they now have to perform the procedure, which is obviously not what we wanted to happen – but it’s necessary because it’s going to give our babies the best chance of surviving.
“So we’re just waiting to go in and we’re just hoping and praying for the best, really. I feel absolutely gutted because I was really hoping we wouldn’t be in this position.
“It’s obviously really scary because there’s so many things that can happen. Pray for us, please.”
Prior to that, Nelson admitted that she was “hoping and praying” for the survival of her twins.
The Boyz hitmaker broke down in tears as she revealed that she’d been undergoing ultrasound scans twice a week, because of potential “complications”.
In a video shared to Instagram, Nelson explained: “We wanted to let you in on our journey of what we’ve been going through.
“So we are having identical twins which is so exciting – we cannot believe it. But, unfortunately, there are complications that come with having identical twins.
“The type of twins we are having are called mono/di twins, and so normally most twins will have two placentas that they feed off of. But when you have mono/di twins, that means your twins live off one placenta, which can lead to lots of complications – one of them being one baby might take all the nutrients, which, and it’s really awful to say, but could lead to both babies dying.”
