Preterm Birth - Classification

Classification

In humans the usual definition of preterm birth is birth before a gestational age of 37 complete weeks, that is, a birth before the beginning of week number 38. In the normal human fetus, several organ systems mature between 34 and 37 weeks, and the fetus reaches adequate maturity by the end of this period. One of the main organs greatly affected by premature birth is the lungs. The lungs are one of the last organs to develop in the womb; because of this, premature babies typically spend the first days/weeks of their life on a ventilator. Therefore, a significant overlap exists between preterm birth and prematurity. Generally, preterm babies are premature and term babies are mature. Prematurity can be reduced to a small extent by using drugs to accelerate maturation of the fetus, and to a greater extent by preventing preterm birth.