Two out of my 3 children was prem. Jake was 8 weeks early and Leann was 9 weeks early. Thankfully due to a trial i was put on or just by chance Lily-Mae was born at 1 day off 37 weeks
The way i got the corrected age is take the weeks the baby was off early the age baby is now, dont know if thats correct, so i guess even after 2 premies it still confuses me. They do this till baby is about 1 yr so they dont show behind in development. But regarding weaning (iron levels) and injections they go on actual age of baby.
Its amazing how quick they catch up thought