So you are expanding your family, congratulations! Yes, adding a new baby to the mix will come with its own set of challenges but I found it was easier transitioning to a family of four (with two under two!) than I thought it would be. Below are the must-have items for your second baby. Some are obvious (like diapers) and others you might not have thought of (such as new entertainment for your first child). I hope you find this list of products for your second baby registry helpful.