My DD's birth should have been traumatic but I dont think it's had any lasting emotional effects.
I didnt have a great pregnancy - lots of bleeding, hospitalisation a couple of times due to early labour, placenta praevia, cholestasis of pregnancy, polyhydramnios... Then I was induced at 36 weeks because of high BP and liver issues which ended in her heart stopping seven hours into labour resulting in an emergency caesarean where I lost over a litre of blood.
She had jaundice. She was allowed home five days post birth but was then readmitted to the SCN for a couple of days two days later...

Not sure, maybe I was too naive to let it get the best of me. I was just so grateful to have this beautiful bundle of pure love that everything else just kind of faded away

So, the short answer is, in my opinion, I dont think the first birth is inherently traumatic. Everyone has different levels of coping and resilience, just as every birth is different. Some, like me, just get lucky.