It was unclear at press time whether the actress' pregnancy would be written into the drama. Her co-star, Chyler Leigh, who plays her half-sister, Lexie, is also pregnant. Chyler's pregnancy has not been written into the script.
Ellen and Chris, a music producer, married in November 2007.
The actress is one of several women in primetime to fall pregnant this television season.
As previously reported on AccessHollywood.com "Ugly Betty's" Ana Ortiz, "Brothers and Sisters" star Rachel Griffiths, "Gossip Girls" Kelly Rutherford," and "How I Met Your Mother" co-stars Alyson Hannigan and Cobie Smulders are all pregnant.
Chyler told Access earlier this year that her pregnancy is being hidden by medical props.
"I've hit the six month mark and I'm totally showing now," Chyler said. "So you'll begin to see me carrying various medical items (charts, notepads, etc.) more often. The oversized scrub top under my normal jacket isn't completely cutting it. I keep wondering when the transition from carrying charts to pushing wheelchairs to pushing gurneys to close up face shots in the OR will happen. I guess the positive is, I'll have really buff arms from all the carrying and pushing of random medical equipment."