In many parts of the world, pregnant women don't have baby showers -- but new moms do. The origins of this practice often center around the risk of miscarriage. In Jewish communities, for example, baby showers are traditionally not held until after a baby is born due to the old belief that attention given to the unborn child could also attract bad luck. In some cases, Jewish parents might not buy anything for a baby -- or even discuss names -- until after he's born [source: Rich].
In many Muslim communities, friends and family host a baby shower for new parents on the baby's sixth or seventh day. This co-ed event is a combination feast, party and naming ceremony, and attendees bring gifts for the baby [sources: Baby Center, McKinley].
If your family doesn't already have a post-birth shower tradition, the timing makes it an ideal one to adopt: After several days, most parents are settling into their new roles and ready to show off their baby. Plus, if you're the easily-exhausted-by-visitors type, the event prevents a constant stream of well-wishers who unwittingly interrupt nap time.