Where does newborn come into this? It says “youngest”, which sure I guess could be a newborn, but my youngest is 22 years old.
It’s been a while since I had my kids, but it took about a month for the paperwork to be processed for them to get birth certificates. They never mailed them to us, but we were told that after a month we should be able to go to the country clerk’s office to pick them up.
Aside from that, when signing up for benefits from an employer, in my previous experiences I had X number of days to get my paperwork in for finalization. Even if this were a newborn situation, there’s enough paperwork from the hospital to generally appease HR types till the real one is available.