Jessica Rotter, 35, had her baby boy, then in the room next door, her grandson was born to her 17 year-old daughter, Briana Guerrero.
"In 20 years of practising, I've seen a lot,' said Dr Alex Lipowich at the Alexian Brothers Medical Center. "I have never delivered a mother and daughter combination on the same day. I can't believe that's very common."
Briana went into labour on Monday night and went to hospital with her heavily pregnant mum, Jessica, who then realised on Tuesday afternoon that her baby was also coming - almost three weeks early.
"We were in the room next to each other," said Briana. "I could hear her and she could hear me. She was a trouper, and the doctor said she did a great job."
"I thought it was sympathy pains at first," Jessica told the Chicago Daily Herald. "I was crying. I was upset because I couldn't be with her.
We were in the room next to each other. I could hear her and she could hear me. She was a trouper, and the doctor said she did a great job.
Jessica gave birth to a 20-inch baby who weighed 7lbs 10oz, six hours before her daughter had Ayden, who weighed a whopping 9lbs 9oz.