Have you ever had an infant who tended to stop breathing when they were asleep?

She has an appointment with the pediatrician in Wichita at 2:30 today.
Just wanted to be sure you knew we weren’t going to take action solely on what is said here.
Here’s the background: She had fraternal twins in January, 5 weeks premie. As far as premie, though, they did alright. Kale was just under 5 pounds, Savannah was just over.
They were released after 3 weeks, with an all clear, and sent home with breathing monitors.
The Dr. took them off of the monitors about 3 weeks ago.
Savannah has always been the bigger of the two. They’re both well over 10 pounds now, so physically they’re doing well.
Last night Savannah quit breathing. Corrie realized this, kind of shook her, and she started breathing again. She started by taking a gasping choke of air.
She did it again this morning.
I’ve been Googling and have found this is not unusual…but it would sure scare the crap out of me. I mean, my thought would be “What would have happened if I didn’t catch it???”
Have you ever experienced this?