The woman on the left is Chontel Duncan, a fitness model and former Miss Universe contestant from Australia. In this November photo, which this week went viral, she was 21 weeks pregnant. She is due to give birth at the end of March.
On the right is her friend Natalie Smith, who was due at the beginning of March with her third child.
"Each woman carries differently and this most certainly doesn't mean one is doing something wrong or not healthy," Duncan wrote on Instagram. "We both have healthy growing babies and we both have had incredible pregnancies so far."