A premature infant is a baby born before 37 weeks gestation.

At birth, a baby is classified as one of the following:

• Premature (less than 37 weeks gestation)
• Full term (37 to 42 weeks gestation)
• Post term (born after 42 weeks gestation)

If a woman goes into labor before 37 weeks, it is called pre-term labor. Often, the cause of pre-term labor is unknown. Multiple pregnancy (twins, triplets, etc.) makes up about 15% of all premature births.

The following health conditions and events in the mother may contribute to pre-term labor:

• Preeclampsia
• Kidney disease
• Diabetes
• Infection
• Heart disease
• Lack of prenatal care
• Poor nutrition
• Young age (a mother age younger than 18)
• Substance abuse

A woman who has had any of the following is at increase risk of pre-term labor:

• Previous pre-term delivery
• Unexplained high alpha-fetoprotein level in the second trimester
• Untreated disease or infection (such as urinary tract infection or infection of the amniotic membranes)
• Problems with the uterus or cervix
• Premature rupture of the membranes or placenta previa

A premature infant has organs that are not fully grown. The infant needs special care in a nursery until the organ systems have developed enough to sustain life without medical support. This may take weeks to months.

A premature infant will have a low birth weight - less than 5.5 pounds (2500 grams). Common symptoms in a premature infant include:

• Respiratory problems such as hyaline membrane disease (also known as respiratory distress syndrome or RDS)
• Episodes of absent breathing (apnea)
• Poor feeding
• Thin, smooth, shiny, almost translucent skin
• Transparent skin (can see veins under skin)
• Wrinkled features
• Soft, flexible ear cartilage
• Body hair
• Weak cry
• Usually inactive -- however, may be unusually active immediately after birth
• Enlarged clitoris (female infant)
• Small scrotum, smooth without ridges (male infant)

This list may not be all inclusive.

The infant may have a low body temperature and show signs of breathing problems.

Common tests performed on a premature infant include:

• Chest x-ray
• Blood gas analysis
• Blood tests to check glucose, calcium, and bilirubin levels

When premature labor develops and cannot be stopped medically, the health care team will prepare for a high-risk birth. The mother may be moved to a center that specifically cares for premature infants, for example, a neonatal intensive care unit (NICU). In some cases, medicines called steroids may be given to the mother in help the baby's lungs grow. When born, the baby is moved to a high-risk nursery. The infant is placed under a warmer or in an machine called an isolette, which controls the air temperature.

Since infants are usually unable to coordinate sucking and swallowing before 34 weeks gestation, your baby may have a feeding tube placed into the stomach. In very premature infants, feedings may be done through a vein (intravenously).

If the infant has breathing problems, a tube may be placed into the windpipe (trachea). A machine called a respirator will help the baby breathe. Oxygen is given.

Nursery care is needed until the infant reaches a body weight of about 5 pounds and is able to feed by mouth and maintain body temperature. In very small infants, other problems may complicate treatment and a longer hospital stay may be needed.

There are multiple support groups for parents of premature babies. Ask the social worker in the neonatal intensive care unit.

Prematurity was formerly a major cause of infant deaths. Improved medical and nursing techniques have increased the survival of premature infants. A greater chance of survival is associated with increasing length of the pregnancy. Of babies born at 28 weeks, approximately 80% survive.

Prematurity is not without long-term effects. A large number of premature infants have medical problems that continue into childhood or permanently. As a rule, the more premature an infant and the smaller the birth weight, the greater the risk of complications. It must be stressed, however, that it is impossible to predict the long-term outcome for an individual baby just on the basis of gestational age or birth weight.

Possible complications include:

• Hyaline membrane disease (respiratory distress syndrome)
• Bleeding into the brain (intraventricular hemorrhage)
• Retinopathy and associated visual loss or blindness
• Bronchopulmonary dysplasia (BPD)
• Heart disease
• Severe intestinal inflammation (necrotizing enterocolitis)
• Jaundice
• Infection or septicemia
• Anemia
• Low blood glucose (hypoglycemia)
• Delayed growth and development
• Mental-motor retardation

Call your health care provider if you are pregnant and believe you are going into labor prematurely.

If you are pregnant and not receiving prenatal care, call your health care provider or your state's department of health. Most state health departments have programs that provide prenatal care to mothers, whether or not they have insurance or are able to pay.

One of the most important steps to preventing prematurity is to receive prenatal care as early as possible in the pregnancy, and to continue such care until the baby is born. Statistics clearly show that early and good prenatal care reduces your chance of premature birth and related deaths.

Premature labor can sometimes be treated or delayed by a medication that blocks uterine contractions. Many times, however, attempts to delay premature labor are not successful.