Many premature infants are resilient and surprise everyone by overcoming great odds. But premature infants are also vulnerable to infection and to complications related to immature body organs. Expect that your infant can progress for several days but may then have a medical setback.

With each additional week of prematurity, a newborn is at greater risk of having medical problems. Infants who have reached their 32nd week of development before birth are considered less at risk for complications than those who are born earlier.

The most common complications of prematurity result from immature organs and an immature immune system and include:

• Low blood pressure.
• Low blood sugar.
• Anemia.
• Respiratory distress syndrome.
• Chronic lung disease (previously known as bronchopulmonary dysplasia). For more information, see the topic Chronic Lung Disease in Infants.
• Necrotizing enterocolitis. For more information, see the topic Necrotizing Enterocolitis.
• Patent ductus arteriosus. For more information, see the topic Congenital Heart Defects.
• Infection (including sepsis).
• Retinopathy of prematurity.
• Intraventricular hemorrhage, or bleeding in the brain, which can result in cerebral palsy or mental retardation. For more information, see the topic Cerebral Palsy.
• Inguinal hernia. For more information, see the topic Inguinal Hernia.

Any infant born before term (before 37 completed weeks' gestation) has an increased risk of developing medical complications.

• Infants born at 32 weeks' gestation or older are least likely to develop complications.
• With each additional week of prematurity before 32 weeks, risks begin to increase dramatically.
• Infants born at 23 to 26 weeks' gestation are extremely underdeveloped and have a significantly higher risk of death and disability. Parents of these infants are likely to be faced with difficult life-or-death medical decisions.

How can I make informed decisions about my extremely premature infant?