With each additional week of prematurity, a newborn is at greater risk for having medical complications. Infants who have reached their 32nd week of development before birth (32 weeks' gestational age) are considered less vulnerable to complications than those who are born earlier. The most common complications of prematurity result from immature organs and an immature immune system and include:
Anemia, which is a shortage of red blood cells. It can deprive the body of needed oxygen. Mild anemia may not require treatment. More severe anemia is treated with blood transfusions or with a medicine (erythropoietin) that improves the body's ability to produce red blood cells.
Respiratory distress syndrome (RDS), which makes breathing difficult. Treatment includes breathing assistance and artificial surfactant (immature lungs do not make surfactant on their own to keep air passageways from sticking shut).
Chronic lung disease. Damaged tissue in the newborn's lungs causes breathing and health problems. Oxygen therapy, medicine, and nutritional therapy can help the disease slowly heal over time. For more information, see the topic Chronic Lung Disease.
Necrotizing enterocolitis, which is infection and inflammation of the intestinal lining. It can be mild or severe, leading to bowel blockage and tissue death, and can be life-threatening. The newborn is fed intravenously to allow time for the intestines to heal. Antibiotics are sometimes used to prevent or treat infection. Surgery is sometimes needed. For more information, see the topic Necrotizing Enterocolitis.
Patent ductus arteriosus, a blood vessel that allows blood to pump from the heart to the lungs. In full-term infants, this blood vessel closes around the time of birth. The more premature the infant, the more likely the ductus arteriosus is to remain open, which can cause complications. Treatment can include medicine or surgery. For more information, see the topic Congenital Heart Defects.
Retinopathy of prematurity (ROP), or poor retina development, which can lead to impaired eyesight. Infants with ROP or who are at risk for ROP need to be checked frequently by an eye specialist (ophthalmologist).