“It's too late to pull out now.”

Challenges of impending parenthood turn the lives of five couples upside down. Two celebrities are unprepared for the surprise demands of pregnancy; hormones wreak havoc on a baby-crazy author, while her husband tries not to be outdone by his father, who's expecting twins with his young trophy wife; a photographer's husband isn't sure about his wife's adoption plans; a one-time hook-up results in a surprise pregnancy for rival food-truck owners.