Australian author Graeme Simsion’s first novel, The Rosie Project, was an international publishing phenomenon, selling over a million copies in more than forty countries. The novel's hero is, according to The Guardian, one of those rare fictional characters – like Adrian Mole or Bridget Jones – destined to take up residence in the popular consciousness. In the highly anticipated sequel, The Rosie Effect, Don Tillman and Rosie are married and living in New York. Don has been teaching while Rosie completes her secondyear at Columbia Medical School. Just as Don is about to announce that his philandering best friend from Australia is coming to stay, he discovers Rosie is pregnant. 

Don instantly becomes an expert in all things obstetric. But between immersing himself in a new research study on parenting and implementing the Standardised Meal System (pregnancy version) Don’s old weaknesses resurface. While he strives to get the technicalities right he gets the emotions wrong, and risks losing Rosie.