Episode 18 of Grey's Anatomy, titled Idle Hands, airs Thursday on ABC and Meredith Grey expresses her worries about her baby being blind, deaf or having any other problems.

Fans will see Grey and her husband, Derek Shepard, find out the gender of their baby but before they do, they couple lay in bed and discuss concerns about their unborn child.

In reality, Grey is the one who worries while Shepard tries to console her. In a sneak peek clip from Idle Hands, shown below, the couple lay in bed and Grey says, "Her eye sight is developing this week. Unless it's not, unless she's blind."

Shepard reassures his wife "she's not blind, or he's not" and then "or if he or she is, that's fine. Blind is fine." Grey continues on by saying, "maybe it can't hear...maybe it's deaf."

Shepard, trying to be positive, tells her "deaf is fine. Helen Keller went to Harvard."

"OK, well what if it's not fine? What if its absorbed twin body? Two heads, extra arms," she added, though Shepard told her to stop. "I'm just saying, if anyone's gonna have a baby with two heads, three arms and 11 toes it's gonna be me."

A promo video for episode 18 reveals that Shepard goes "McCrazy" over baby troubles. Not that anything is wrong with his child, but his wife turns out to be his "biggest challenge in his life." Grey is a pregnant, paranoid and hormonal wife.

In Idle Hands the couple also learns the sex of their baby and whatever the gender is makes Miranda Bailey very happy, as she is seen shrieking for joy in a preview clip for the episode.

Episode 18 of Grey's Anatomy, part of its ninth season, airs Thursday, March 21, at 9 p.m. ET on ABC.