Full term and early term
Although a typical pregnancy lasts 40 weeks, a baby is considered full term after the 37th week of pregnancy. Babies born before 37 weeks are considered premature.
Premature babies often have medical problems that vary in complexity based on each case. The earlier a baby is born, the more severe the medical problems tend to be. Depending on the gestational week that the baby is born in, they may be:
- Late preterm — born between 34 and 36 weeks
- Moderately preterm — born between 32 and 34 weeks
- Very preterm — born at or before 32 weeks
- Extremely preterm — born at or before 25 weeks
Most premature births happen after 34 weeks of gestation, in the late preterm stage. Currently, the premature birth rate in the United States is approximately 11.5 percent.