Premature babies are more likely to suffer from medical complications. Very premature babies born before 28 weeks are particularly vulnerable. Unfortunately, some of the health problems related to premature birth can last a lifetime. Premature babies are often small, with low birth weight (often less than 5 pounds), and may need help breathing, eating, fighting infection, and keeping themselves warm. In some cases, their organs may not be ready for life outside the uterus and may be too immature to function correctly.