Hostess of the Shower?
Anyone can plan the shower -- family members, friends and/or co-workers. A mommy-to-be can have many showers but it is wise to consult her or her mother (if it is a surprise) so that the themes can all be different -- this also avoids duplication of gift items.
Before the Baby or After the Baby is Born?
For first-time mothers, showers before the baby arrives are great fun for her to look forward to in the last month of her pregnancy -- and she and the daddy can play and dream with all the gifts while awaiting their bundle of joy. Mothers having their second or more children, sprinkles can be held before or after the baby is born. The up side of holding the shower after the baby's birth is that gifts can be chosen by the sex of the baby.