Near death experiences are believed by many to cause people to be closer to the spiritual world, seeing that they die or nearly die, crossing or nearly crossing the veil before returning.
The only birth related belief is that of being "born with a veil" (you can look that up in google) and birthmarks that look like the image of something.
My family believed that the woman while pregnant must be very careful not to be startled by something. And that no one should ever frighten or startle her on purpose. They believed that the child would be affected physically in a way that corresponded to the scare. For instance, a family member of mine became startled by a sponge that touched her back as it fell off of something. The child was born with a large strawberry birthmark on the exact place the sponge touched the mother's back. There are other examples in my family but ones so wild they're hard for even me to believe. But it is a belief surrounding pregnancy and birth, so I thought I would mention it.