My midwife told me black women have more chances of twins?

There was a lady next to me waiting for a appointment and we got talking! Her bump was soo big and she said she struggles carrying around her twins. I helped her get up as she was struggling!

I got called for my appointment and I said to my midwife I was talking to a lovely lady and having twins must be hard on your body and are twins common. She told me that black women are much more likely to carry twins, she also carried twins and is originally from Barbados! I was soo amazed but as my blood pressure was low we moved on to other things.

Is this actually true and if so how and why?