Successful and single businesswoman Kate Holbrook (Fey) has long put her career ahead of a personal life. Now 37, she's determined to have a kid of her own until she discovers she has no chance of getting pregnant. Undaunted, Kate allows working girl Angie (Poehler) to become her unlikely surrogate. But her well-organised strategy is turned upside down when her Baby Mama shows up at her doorstep with no place to live. An unstoppable force meets an immovable object as structured Kate tries to turn vibrant Angie into the perfect expectant mom. In a comic battle of wills, they will struggle their way through preparation for the baby's arrival.