When shopping for twins, at a minimum, you'll need to buy all the items you'd need for a single baby, However, sometimes, you'll need to buy double, such as with diapers, bottles and pacifiers, and car seats. Sometimes, you can use one item that both twins can share, such as a baby monitor or an infant bath tub (one at a time, please!). Alternatively, you might buy a twin-specific product, such as a nursing pillow or stroller designed for twins.