What is prematurity?

A baby born before 37 weeks of pregnancy is considered premature or born too early. Other terms used for prematurity are preterm and preemie. The number of premature births in the U.S increased from 1990 to 2006 and has since been declining. Twins and other multiples are more likely to be premature than single birth babies. 

Many premature babies weigh less than 5 pounds, 8 ounces (2,500 grams). They may be called low birth weight. Even older, heavier preemies are still at risk for some problems. 

What causes prematurity?

Premature birth may have a number of causes. About 4 out of 5 premature births are because of  issues that directly cause early labor and birth, such as those listed below. Other problems can make the mother or baby sick and need early delivery. Sometimes the exact cause for a premature birth is unknown. This can be true even though the mother may have done everything right during the pregnancy. 

Four things that may cause premature labor are:

  • Being pregnant with more than one baby
  • Bleeding or other problems with the uterus
  • Stress
  • Infection in the uterus or elsewhere in the body

Who is at risk for prematurity?

Many women have no known risk factors for premature birth. But several things can make premature birth more likely.

Women with these risk factors are more likely to deliver early:

  • Having had a previous preterm labor or birth
  • Getting pregnant within a short time (less than a year) after having had a baby
  • Carrying twins, triplets, or more babies at one time
  • Having an abnormal cervix or uterus
  • Being younger than 16 or older than 35
  • Being African American
  • Having long-term health problems such as heart disease or kidney disease
  • Smoking
  • Using illegal drugs such as cocaine

In addition, women who develop any of the following problems during pregnancy are more likely to deliver early:

  • Infections
  • High blood pressure
  • Diabetes
  • Blood-clotting problems
  • Problems with the placenta
  • Vaginal bleeding

Certain developmental problems can put unborn babies at higher risk for prematurity.

What are the symptoms of prematurity?

Each baby may show slightly different symptoms. The following are the most common symptoms of a premature baby:

  • Small size. Premature babies often weigh less than 5 pounds, 8 ounces.
  • Thin, shiny, pink, or red skin. You may be able to see veins through the skin.
  • Little body fat
  • Little scalp hair. But the baby may have lots of soft body hair (lanugo)
  • Weak cry
  • Low muscle tone
  • Male and female genitals are small and not yet fully developed

The symptoms of prematurity may look like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.

How is prematurity diagnosed?

A baby born before 37 weeks of pregnancy is considered premature or born too early. Prematurity is defined as:

  • Early term infants. Babies born between 37 weeks and 38 weeks, 6 days.
  • Late preterm infants. Babies born between 34 weeks and 36 weeks, 6 days.
  • Very preterm. Babies born at or below 32 weeks.
  • Extremely preterm. Babies born at or below 28 weeks.

How is prematurity treated?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment may include:

  • Corticosteroid medicine for the mother to help the baby’s lungs and other organs grow and mature before birth
  • Watching the baby’s temperature, blood pressure, heart and breathing rates, and oxygen levels
  • Temperature-controlled bed
  • Oxygen given by mask or with a breathing machine called a ventilator
  • IV (intravenous) fluids, feedings, or medicines
  • Special feedings with a tube in the stomach if a baby can’t suck
  • X-rays or other imaging tests
  • Skin-to-skin contact with the parents (kangaroo care)

What are the complications of prematurity?

Premature babies are cared for by a neonatologist. This is a doctor with special training to care for newborns. Other specialists may also care for babies, depending on their health problems.

Premature babies are born before their bodies and organ systems have completely matured. These babies are smaller than they would have been if they were born at full term. They may need help breathing, eating, fighting infection, and staying warm. Extremely premature babies, those born before 28 weeks, are at the greatest risk for problems. Their organs and body systems may not be ready for life outside the mother’s uterus. And they may be too immature to function well.

Some of the problems premature babies may have include:

  • Keeping their body temperature steady or staying warm
  • Breathing problems, including serious short- and long-term problems
  • Blood problems. These include low red blood cell counts (anemia), yellow-color to the skin from breaking down old red blood cells (jaundice), or low blood sugar levels (hypoglycemia).
  • Kidney problems
  • Digestive problems, including trouble feeding and poor digestion. In some cases there may be inflammation and death of parts of the intestine (necrotizing enterocolititis).
  • Nervous system problems, including bleeding in the brain or seizures
  • Infections

Premature babies can have long-term health problems as well. Generally, the more premature the baby, the more serious and long-lasting the health problems may be.

Can prematurity be prevented?

More babies are surviving even though they are born early and are very small.  But it is best to prevent preterm labor if possible.

It's important to get good prenatal care while you are pregnant. Your healthcare provider can help find problems and suggest lifestyle changes to lower the risk for preterm labor and birth. Some ways to help prevent prematurity include:

  • Stopping smoking if you smoke. You should stop smoking before you are pregnant.
  • Finding out if you are at risk for preterm labor
  • Learning the symptoms of preterm labor
  • Getting treated for preterm labor

Your healthcare provider may give you the hormone progesterone if you are at high risk for preterm birth. Progesterone can help if you have had a previous preterm birth. 

How is prematurity managed?

Premature babies often need time to catch up in both development and growth. In the hospital, this catch-up time may mean learning to eat and sleep, as well as steadily gaining weight. Babies may stay in the hospital until they reach the pregnancy due date. They may be cared for in a neonatal intensive care unit (NICU).

Talk with your baby's healthcare provider about when your baby will be able to go home. In general, babies can go home when they:

  • Have no serious health conditions
  • Can stay warm in an open crib
  • Take all feedings by breast or bottle, maintaining their expected growth rate
  • Have no recent periods of not breathing (apnea) or low heart rate

Before discharge, premature babies need an eye exam and hearing test to check for problems related to prematurity. You must be able to give care, including medicines and feedings, before your baby can go home. You will also need information about follow-up visits with the baby's healthcare provider and vaccines. Many hospitals have special follow-up healthcare programs for premature and low-birth-weight babies.

Even though they are otherwise ready to go home, some babies still have special needs. This includes things such as extra oxygen or tube feedings. You will learn how to take care of your baby if he or she needs these things. Hospital staff can help set up special home care.

Ask your baby’s healthcare provider about staying overnight in a parenting room at the hospital before your baby goes home. This can help you adjust to caring for your baby while healthcare providers are nearby for help and reassurance. You may also feel more confident taking your baby home when you know infant CPR and safety.

Premature babies are at increased risk for sudden infant death syndrome (SIDS). You should always put your baby down to sleep on his or her back.

Key points about prematurity

  • Babies born before 37 weeks of pregnancy are considered premature or born too early.
  • Many premature babies also weigh less than 5 pounds, 8 ounces (2,500 grams). They may be called low birth weight.
  • Premature babies can have long-term health problems. In general, the more premature the baby, the more serious and long-lasting the health problems may be.
  • Prenatal care is a key factor in preventing preterm births and low-birth-weight babies.
  • Premature babies are at increased risk for sudden infant death syndrome (SIDS).
  • Even though they are otherwise ready for discharge, some premature babies still need special care when they go home.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.