When Should A Pregnant Woman Stop Running?

Many women run throughout their pregnancy, but what are the risks involved? INSIDE EDITION has what you need to know.

One may do a double take when you see Catey Ball out for a run, simply because she's nine months pregnant with her ninth child.  

The avid runner pounds the pavement three times a week through her neighborhood near Provo, Utah. The fact that her due date is just a week away hasn't slowed her down.

"I feel great," she said.

But not everyone thinks jogging while expecting is a good thing. When a photo of a woman running with her pregnant belly hit the web it triggered a slew of nasty comments. She was called "selfish" by one blogger, another wrote, "Someone should call the child protection agency!"  

Reese Witherspoon was recently photographed running with her growing baby bump. And who can forget "Marathon Mom" Amber Miller? Miller gave birth just seven hours after crossing the finish line at last year's Chicago marathon.

Miller said, "The race was definitely easier than the labor."

But is there ever a time when an active mom-to-be should stop running?

Dr. Jacques Moritz, Director of Gynecology St. Luke's Roosevelt told INSIDE EDITION, "You have to listen to your body. When you are loosing breath, that means the baby is losing oxygen, back off."