Nine months pregnant Lorna Forrest, 33, and eight months pregnant Joanna Gallagher, 29, had their bumps painted to help promote the Macmillan Cancer Support event.
Midwife Joanna Gallagher, from East Kilbride, said: "We certainly drew quite a few looks from people on the street. Most people seemed to find it very amusing, although it was a bit strange having people staring at my stomach.
"It was great fun and I'm glad I was able to do something to help such a good cause."
Lorna, head of funding at the Big Lottery Fund, added: "We had really good fun showing off our bumps and it will be great to be able to show my child pictures in the future. The World's Biggest Coffee Morning is a really good cause and a great excuse to eat cake so I hope people across Glasgow get involved and help make the event a success."
The event takes place on Friday.