Not Even Pregnancy Can Stop These Marathoners From Running

— -- When Kara Goucher competes at this Sunday’s New York City Marathon, she will do so with her 4-year-old son, Colt, cheering her on.

Goucher, 36, went for a run the day she gave birth to Colt four years ago. Now, she is part of an emerging trend of professional female runners, as profiled recently by the New York Times, maintaining a running career while raising a family.

“I had to plan in a certain window,” Goucher told ABC News of the difficulty of getting pregnant amid training and sponsorship schedules. “Every other even year is an off year [so] that’s the year we try to get pregnant.”

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“It’s stressful,” she said. “If I wasn’t pregnant by a certain date, I’d have to wait another four years.”

Clara Horowitz Peterson is another elite runner who, like Goucher, gave birth without giving up her running profession.

“I ran all nine months with all three pregnancies,” Peterson, 30, told ABC News. “The babies were growing progressively and I was feeling fantastic so I went for it.”

Peterson is now pregnant with her fourth child. She says she chose to have kids earlier in life, hoping to peak later in her career.

“If I go too many days without running, it’s like I haven’t brushed my teeth for a week,” she said. “It’s just something that I need to do.”

Running while pregnant made headlines last summer when America watched Olympian Alysia Montano run the 800-meter race at the U.S. Track and Field Championships while she was 8.5 months pregnant.

Montano, then 28, drew some criticism for racing so late into her pregnancy but fellow mother-runners like Peterson say they listen to their doctors and know what is best.

“The bottom line is I’m an elite athlete,” Peterson said. “I know my body better than anybody and I know what’s OK and what isn’t.”