4-10 days old is the best age to photograph newborn babies.
At this age, they are more settled and sleep a lot. Have fewer skin problems (such as milk rash) and are naturally more curled up. Things like colic can become noticeable after two weeks of age. Babies at this age tend to go into particular curly type poses much more naturally than older babies. Likewise, they also don’t mind having their clothes off if they are kept warm.
The result is a session that runs far more smoothly — producing some gorgeous sleepy baby photos. Awake portraits can be awesome too. But for the majority of the session, posing is more comfortable if they are drowsy.