They aren't recommended for number of reason one of them being over heating risk and the fact it's not a flat surface and baby shouldn't be left unattended whilst on this
No they’re not safe. Babies need to lie on a a flat, hard surface. Sleeping overnight isn’t a concern for flat heads. Providing they’re not lying in their backs all day too, they’ll be fine.
Definitely not sleep safe. Plenty of tummy time, baby wearing and lying on different surfaces will ensure they don't get a flat head.
I got one of these with my first and shouldn’t have bothered. I spent all my time checking and researching it really didn’t help me or him sleep in the end He had a little flat spot which is normal as they are on their back a lot however tummy time and as he got older being able to sit up and spent time off the back of his head made sure everything evened out
They don’t need a pillow. My little one is 21 months old and still hasn’t got one. Xx
What I've read and been told is that they're not considered safe because it reduces the baby's ability to use their startle reflex, which keeps them safe. It also can cause overheating as they can't regulate their own body temperature. I've also heard that it's fine as long as you're watching them, but if you're both asleep, or they're in another room, no pillow is best. As long as you're ensuring your baby is getting good amounts of tummy time I think you shouldn't have to worry too much about a flat head. Maybe talk to your midwife about this specific type of pillow to be sure?