Welcome new little ones to the neighborhood. When I was growing up, every time one of the families had a new baby, the neighbors would decorate the families’ front porch with pink or blue ribbons. It was a small gesture, but a way of simultaneously announcing to everyone the baby’s birth and welcoming the baby into our community.
I would add, it doesn't have to be gendered. A stork will get the message across. Consider that a birth in the neighborhood is also a good time for other parents to clean house and ask if the new ones would like some baby things. In most families, the stuff barely gets used before it's outgrown, so passing it around makes sense.