Speaking to People magazine, the famous reality stars younger brother said that although he is "happy" for them, he would rather wait till he is married before having a child.
"I'm so proud of my sisters, but I'll be married before I have a baby," Rob told the US gossip magazine at a New Year's Eve countdown in Miami on Monday.
"It's beautiful. It's a blessing. The New Year, we've got another child coming, so that's great. Kim's never had a baby, so it's going to be a beautiful blessing," Rob enthused.
'Everyone focussing on just the baby'
He also hinted Kim - who is still legally married to estranged
husband Kris Humphries - won't be walking down the aisle with Kanye
anytime soon and wants to concentrate on motherhood for the time being.
"No idea, no idea. I'm sure that will come down the road, but right now I'm sure everyone's focusing on just the baby going on right now. I'm sure that's something in the future," he said.
The Daily Mail reports that Rob, who split from British singer Rita Ora amidst a flurry of controversy, said that nobody is worrying too much about another wedding right now.
"I think everyone is just excited about and focused on the baby right now. Kim and Kayne are over the moon happy. I'm so excited to be an uncle again!"