Should Jewish parents-to-be throw a baby shower? Why or why not? What is the origin of the baby shower (amongst Jews specifically) if any? For clarification, I am referring to the party before the child's arrival.
To the best of my knowledge there is no known source that prohibits baby showers, however most Orthodox Jews generally do not have baby showers for fear of Ayin Hara - evil eye.
The Baby shower is a modern concept, based on consumerism.
The modern baby shower started after WWII during the baby boom era and evolved with the consumer ideology of 1950s and 1960s. In other words, baby showers in the mid-twentieth century not only served an economic function by providing the mother-to-be and her home with material goods that lessened the financial burden of infant care, but purchased “things” also emerged as the principle whereby women make themselves into mothers. The commodities associated with pregnancy and birth served to construct the identity of the fetus as a social being (and often become treasured objects of many women who lose their baby). Rituals of the modern baby shower include “showering” the mother-to-be with presents, making shopping trips organized around the baby-to-be, establishing a playful atmosphere at the shower, and placing the mother-to-be on a chair for her to sit on as she opens her gifts and passes them around for her guests to view (Clarke 2004).
The shower, in many senses, serves to indoctrinate the woman into the special behaviors associated with her new role in society. Paradoxically, though, the cute games played at the shower tend to infantilize the woman and return her to innocence--and the central chair, often decorated, also gestures toward a symbolic return to the virginal, nonsexual state associated with Mother Mary, Queen of the World. The modern baby shower, then, supports the themes regarding the woman’s transition to a more dependent, but pure state while also creating and reinforcing the personal relationships which form the community (Crouch and Manderson 1993).
However, Jewish custom has evolved, so that preparations for a baby are not made until 40 days after conception. This is when the soul traditionally enters the fetus. The main concern is the "evil eye", and for some good reason.
From our very early beginings, the Jewish people have had a hard time giving birth. All of our Matriarchs were barren, and from what I have heard, Jews tend to have a higher than 30% rate of miscarriage that is normally quoted as the norm.
As can be seen from the history of Baby Showers, it's also not a very Jewish value. It would be interesting to learn why the Baby Shower in European and American society moved from being the day after the birth, to sometime before the birth. I suspect it has to do with an increase in medical technology to deal with premature babies.