Babies grow quickly, and if you choose to start with newborn-size clothing, you should be aware that they won't be in those items for very long. However, it's also important not to dress your baby in clothing that is way too big, especially for bedtime. Clothes should fit your baby well enough so as not to pose a suffocation risk. It's best to buy minimal newborn items to make it through the first couple of weeks, keeping in mind that you'll be doing plenty of laundry to keep those items clean.