Moi: Depends on your theme. My friend gave stickers with my son's name on it. Coloring book of the theme. Balloons. That time I had angry bird theme, so I got angry bird stickers to give away. Party hat, but some children don't like. One friend had a hungry caterpillar theme, gave a magnetic board with various characters for fishing. I won't give food items but I had junk food in those goodie bags before. Depending on age, maybe can give cheap rattle for sound. Or you can buy foam alphabet set, give them a few letters or just their nAmes or initials.
Nattan: don't wait too long. The older we get, the more complications we face, or just more tired. An acquaintance has two teenage children, she's now 39 to 41, she finds this pregnancy super tough. But not immediately so that your #1 can be breastfed for a year and your body can rest properly.