In the writer-director's new film, Ben Stiller and Naomi Watts' characters befriend a younger, free-spirited couple.
While some expectant parents wait to find out the sex of their baby, and others want to know after a couple of months of ultrasounds, a growing number of Americans are now using medical techniques to choose the gender of their child.
Jasmeet Sidhu writes in Slate magazine that U.S. parents tend to prefer girls over boys, and are using expensive reproductive procedures to make sure they deliver a daughter.
One gender selection technique, known as preimplantation genetic diagnosis (PGD), involves culturing embryos to find out what sex the child will be. In another method, sperm is sorted based on whether it carries an X or Y chromosome.