"I'm showing a little bit, but for now, the scrubs and the lab coats cover everything," Drew, 30, told Us Weekly Sunday at ABC's Television Critics Association all-star party. "I'll probably be able to get through the next three months without having too much beyond that. After, they'll just use body doubles when they need to."
Drew added that she's already outgrowing her scrubs, "so they had to take all the strings out and get me a bigger size!"
Since this will be the first child for the actress and husband Paul Lanfer, Drew told Us that her Grey's Anatomy costars have been "incredibly helpful" helping them prepare for her January 2012 due date.
"I got great advice about nausea from Ellen Pompeo because I am still dealing with nausea, which is no fun," Drew said. "She's a wealth of information: she's done all the research and looked into every possible way of doing things."
"I've gotten some great advice from Jessica Capshaw, especially about the brand of Pampers I'm supposed to be using. But I'm like, 'Dude, I have some time.' And I had great advice from Chyler Leigh about breastfeeding."
Drew also praised her husband for being a hands-on father-to-be.
"He is literally a dream," she told Us. "He's got this boys' night he's supposed to go to tomorrow night, but he's like, 'No Sarah, you have a full day and I want to make you dinner and make sure you're taken care of…I just want to be here for you and take care of you.'"
"He's become super protective of my energy level and time," she added of Lanfer, whom she wed in 2002. "He's been amazing. I can't ask for a better partner."