The 25-year-olds were due to give birth a day apart but welcomed their babies into the world within 15 minutes of each other.
The pair went into labour at the same time and checked into Henry Ford Macomb Hospital in Detroit's north.
"It's a good thing they put them next to each other so I could run quickly from room to room, but they did great," said Dr Timothy Kim, who delivered both babies.
The girls' husbands even held a friendly bet over which baby would arrive first.
"It was a race between Greg and I. We had a side bet going. The girls, I don't think, really cared too much" Gilbert's husband, Andy, said.
Alison gave birth to a girl named Claire while Amy produced a boy named Garrett.