Screenwriters Tim Kazurinsky and Denise DeClue began work by immersing themselves in the subject of teenage pregnancy, reading articles and speaking directly to teenage mothers. Kazurinsky said: "According to our research about 10,000 U.S. teenagers a week who are pregnant keep their babies. And in every interview we had with young pregnant girls, they all said, 'I never thought it would happen to me.' So we created Darcy Elliot as the kind of smart, with-it girl who would never think it could happen to her".
According to the Wikipedia website, "the promising career of John Zarchen, thought to be on the verge of breakout in the supporting role of Stan's best friend, Chris, literally hit a wall during the shooting, as Zarchen suffered a life-threatening head injury while driving in Hollywood, allegedly under the influence of alcohol. He survived a brief period of being comatose, and actually returned to the film, although director John G. Avildsen, due to his medical absence and [allegedly] disgusted with the actor's disregard for the opportunity and the production, greatly cut down his role".
For actor Randall Batinkoff, one of the nicest parts about making his debut starring role in the movie, was the opportunity to work with actress Molly Ringwald. Batinkoff said: "Molly is a wonderful actress. She possesses the qualities that make Stan's admiration for Darcy very believable. She was so real playing Darcy that it helped me play Stan".
According to The '80s Movie Rewind website, "a baby shower scene was shot but didn't make it into the film. Strangely enough, still photos from that scene are on the box and were used in promotional materials".
Producer Jerry Belson originated as the idea of a story of two teenagers who wager that love and good humor can beat the odds that say teenage marriages can't work and teenage parents are bound to fail. Belson said: "There have been many theatrical films about people being married and having babies, but they've never really done one about teenagers. Even though I realized it was sensitive politically, I still thought it was worth it to do a human story about kids like this".