Preterm-premature babies -LRB- `` preemies '' or `` premies '' -RRB- have an increased risk of death in the first year of life -LRB- infant mortality -RRB- , with most of that occurring in the first month of life -LRB- neonatal mortality -RRB- .

Most die in their first month of life , which is called neonatal mortality .
