Babies born before the 37th week of gestation (preterm babies) are very small and fragile. Birth weights are often less than two pounds. Many of the organ systems are not fully developed, which leads to complications as these infants struggle to survive. Complications include:

1. Inability to breathe or breathe regularly on their own due to underdeveloped lungs

2. Difficulty in body temperature regulation; the baby cannot maintain his or her own body heat

3. Feeding and growth problems because of an immature digestive system

4. Jaundice due to a buildup of bilirubin

5. Anemia due to not enough red blood cells to carry oxygen to tissues

6. Bleeding into the brain

Although after a year or two most preterm babies are developmentally the same as full-term babies, some may still experience breathing difficulties, hearing or vision problems, and learning disabilities.