occurring before 37 weeks of pregnancy.
less than 37 completed weeks of gestation.
Infant born before the end of gestation (37 weeks)
Counting from the first day of the woman's last period, preterm is before 40 weeks.
Delivered/born before 37 completed weeks since the last normal menstrual period of a pregnancy.
labor that begins before the 37th week of pregnancy.
Babies born earlier than 37 weeks.