The invite should have the name or names of the mom-to-be or parents-to-be in case it’s a coed baby shower. Aside to that, other important details are the name of the host or hosts (for a coed party), the location, date, theme of the baby shower, RSVP, contact details of the...
a classic baby shower invitation, like thissweet stork, is the way to go. Include the location, time, and RSVP deadline within the invitation wording. Be sure to include where the couple is registered if gifts are encouraged.