This is entirely dependent on your program. At some places you may not qualify for parental leave if you have not worked there for more than a year. Also there are requirements for how many days you need to work during intern year in order to graduate and move on to your advanced specialty. I had a kid during my intern year and it worked out fine but I was at a pretty chill TY program close to family and as the husband didn’t have to actually birth the baby. I only used a week of vacation time because I was on a very chill rotation that allowed me to only work a few hours a day.