Maybe a package of diapers with a card. Card could include gift card to somewhere like Target where it is possible to buy baby items or diapers.
I used to give 1st year and/or 2nd year (first year goes fast!) sticker calendars. Especially if there is older sib(s). I figured if the parents already had one, they could regift at another shower. Example - Morehead 2nd Year Baby Calendar | Current Catalog