CDC - Preterm Birth-Prematurity - Maternal Infant Health - Reproductive Health

CDC - Preterm Birth-Prematurity - Maternal Infant Health - Reproductive Health

Preterm Birth

Each year, preterm birth affects nearly 500,000 babies—that's 1 of every 9 infants born in the United States. Preterm birth is the birth of an infant prior to 37 weeks of pregnancy. Preterm-related causes of death together accounted for 35% in 2008 of all infant deaths, more than any other single cause. Preterm birth is also a leading cause of long-term neurological disabilities in children. Preterm birth costs the U.S. health care system more than $26 billion each year. 
A developing baby goes through important growth during the final weeks and months of pregnancy. Many organ systems, including the brain, lungs, and liver need the final weeks of pregnancy to develop fully. There is a higher risk of serious disability or death the earlier the baby is born. Some problems that a baby born too early may face include—

• Breathing problems.
• Feeding difficulties.
• Cerebral palsy.
• Developmental delay.
• Vision problems.   [PDF - 118KB]
• Hearing impairment.

Preterm births also may cause heavy emotional and economic burdens for families. Learn more about preterm birth.

Frequently Asked Questions: For Women and Their Families

  [PDF - 2.3MB]

Are some women more likely than others to go into preterm labor and deliver early?

Several factors may increase the likelihood that a woman has preterm labor and delivers early. This preterm birth infographic  [PDF - 2.3MB] gives some examples of these factors by medical and pregnancy conditions, behavioral factors, and social, personal, and economic characteristics. 

Can anything be done to prevent a preterm birth?

Preventing preterm birth remains a challenge because the causes of preterm births are numerous, complex, and poorly understood. However, pregnant women can take important steps to help reduce their risk of preterm birth and improve their general health. These steps are to—

• Quit smoking.
• Avoid alcohol and illicit drugs.
• Get prenatal care as soon as you think you may be pregnant and throughout the pregnancy.
• Seek medical attention for any warning signs or symptoms of preterm labor.

What are the warning signs of preterm labor?

In most cases, preterm labor begins unexpectedly and the cause is unknown. Like regular labor, signs of early labor are—

• Contractions (the abdomen tightens like a fist) every 10 minutes or more often.
• Change in vaginal discharge (leaking fluid or bleeding from the vagina).
• Pelvic pressure—the feeling that the baby is pushing down.
• Low, dull backache.
• Cramps that feel like a menstrual period.
• Abdominal cramps with or without diarrhea.

My last baby was born early. Is there anything I can do in this pregnancy to keep it from happening again?

A progesterone medication (17-alpha hydroxyprogesterone caproate, or 17P) may prevent preterm birth among women who have had a prior preterm birth. The U.S. Food and Drug Administration (FDA) approved hydroxyprogesterone caproate injection (Makena™) to reduce the risk of preterm delivery in pregnant women with a history of delivering early. It is not intended for use in women carrying more than one baby or women with other risk factors for preterm birth. Consult with your health care provider to learn more about this and other drugs, including whether they are safe for use during pregnancy.

I used in vitro fertilization (IVF) or another assisted reproductive technology (ART) to get pregnant. What is my risk of having a preterm birth?

Women who conceived through ART are at higher risk for preterm birth, primarily because they are more likely to be pregnant with more than one baby at a time. More detailed information on ART cycles and preterm birth can be found in the CDC’s 2010 Assisted Reproductive Technology Report.

What should I do if I think I’m experiencing preterm labor?

If you think you are experiencing preterm labor, it is important that you see a doctor right away. If you are having preterm labor, the doctor may be able to give you medicine to help the baby’s lungs mature so that the baby will be healthier at birth.

Is it okay to schedule my baby’s birth once I reach 37 weeks gestation?

Important growth and development occur throughout pregnancy—all the way through the final few weeks. If the mother is healthy, current research indicates that delivery should not be scheduled before 39 weeks gestation.

What is CDC’s Division of Reproductive Health doing to prevent preterm birth?

CDC’s Division of Reproductive Health is engaged in a variety of research and science to practice activities aimed at understanding and reducing preterm births. CDC scientists are collaborating with many partners, including state health departments, university researchers, and other health care professionals to understand why preterm births occur and what can be done to help prevent them. Read about our preterm birth research activities.

Related Links

Video: Is It Worth It? Watch this video from the National Child and Maternal Health Education Program to learn the benefits of waiting 39 weeks until delivery.
Preterm Birth (March of Dimes) The March of Dimes continues its national campaign to help families and communities cope with prematurity.

First Candle First Candle provides support to families that have experienced the death of an infant by offering support groups and a hotline.

Preterm Births The National Library of Medicine (NLM) provides information for health care consumers on preterm births and related topics in maternal and child health.

Early Preterm Birth (ACOG) [PDF - 282KB] This patient education pamphlet was developed by the American College of Obstetricians and Gynecologists (ACOG).

National Prematurity Awareness Month

Nearly a half million babies in the United States—that's 1 out of every 9—are born premature each year. Learn more about premature birth, risk factors, and what you can do.

What is Premature Birth?

It is a birth that is at least three weeks before a baby's due date. It is also known as preterm birth (or less than 37 weeks—full term is 40 weeks). Important growth and development occur throughout pregnancy—especially in the final months and weeks.
The earlier a baby is born, the more severe his or her health problems are likely to be. Although babies born very preterm are a small percentage of all births, these very preterm infants account for a large proportion of infant deaths. More infants die from preterm-related problems than from any other single cause. Some premature babies require special care and spend weeks or months hospitalized in a neonatal intensive care unit (NICU). Those who survive may face lifelong problems such as—

• Intellectual disabilities  [PDF - 64KB].
• Cerebral palsy.
• Breathing and respiratory problems.
• Visual problems including retinopathy of prematurity.
• Hearing loss.
• Feeding and digestive problems.

Risk Factors

Even if a woman does everything "right" during pregnancy, she still can have a premature baby. There are some known risk factors for premature birth. For example, one risk factor is having a previous preterm birth. Additionally, although most black women give birth at term, on average, black women are about 50% more likely to have a premature baby compared to white women. The reasons for the difference between black and white women remain unknown and are an area of intense research.
The other known risk factors are—

• Carrying more than one baby (twins, triplets, or more).
• Problems with the uterus or cervix.
• Chronic health problems in the mother, such as high blood pressure, diabetes, and clotting disorders.
• Certain infections during pregnancy.
• Cigarette smoking, alcohol use, or illicit drug use during pregnancy.

Premature Birth: What to Know

Doctors sometimes need to deliver a baby early because of concerns for the health of the mother or the baby. An early delivery should only be considered when there is a medical reason to do so. If a pregnant woman is healthy and the pregnancy is progressing well, it is best to let the baby come naturally, in its own time.
Although most babies born just a few weeks early do well and have no health issues, some do have more health problems than full term babies. For example, a baby born at 35 weeks is more likely to have—

• Jaundice
• Breathing problems.
• A longer hospital stay.

What Can I Do?

There are things that women can do to improve their health, lower the risk of having a premature baby, and help their baby be healthy. These include—

• Quit smoking and avoid alcohol or drugs.
• See your health care provider for a medical checkup before pregnancy. Get prenatal care as soon as you think you may be pregnant, and throughout your pregnancy.
• Talk to your health care provider about—
  • How to best control diseases such as high blood pressure or diabetes.
  • A healthy diet and prenatal vitamins. It is important to take 400 micrograms of folic acid daily before and during early pregnancy.
  • Concerns about pregnancy and any warning signs or symptoms of preterm labor that will need medical attention.
  • The use of 17 alpha hydroxyprogesterone caproate (17P) if you had a previous preterm birth.
  • Breastfeeding. Breast milk is the best food for babies, whether they are born early or at term.

Warning Signs of Preterm Labor

In most cases, preterm labor begins unexpectedly and with no known cause. It’s important to seek care if you think you might be having preterm labor, because your doctor may be able to help you and your baby.
The warning signs are—

• Contractions (the abdomen tightens like a fist) every 10 minutes or more often.
• Change in vaginal discharge (leaking fluid or bleeding from the vagina).
• Pelvic pressure—the feeling that the baby is pushing down.
• Low, dull backache.
• Cramps that feel like a menstrual period.
• Abdominal cramps with or without diarrhea.

Birth is a complex and wonderful process. Fortunately, the outcome for most women is a full term, healthy baby. More research still is needed to understand the risk factors for premature birth, such as how family history, genetics, infections, race and ethnicity, nutrition, and environment may work together to put some women at greater risk for a premature delivery.

More Information

• Preterm Birth—CDC's Division of Reproductive HealthPromotes optimal reproductive, maternal, and infant health. CDC scientists and their partners are collaborating with states, university researchers, and partners in health care to understand why preterm births occur, and what can done to prevent prematurity.
• Preterm Labor and Birth
  More information from the National Institute of Child Health and Human Development.
• Premature Babies
  The National Library of Medicine provides links to the latest news and research on preterm birth.
• Premature Birth
  Learn more information about the care of premature babies from the American Academy of Pediatrics.
• Healthy PregnancyLearn how to be healthy (before, during, and after pregnancy) and give your baby a healthy start to life.
• CDC's National Center on Birth Defects and Developmental Disabilities
  Promotes the health of babies, children, and adults, and enhances the potential for full, productive living.

March of Dimes Resources

• Prematurity Campaign
  More information about premature birth and the March of Dimes prematurity campaign.
• Share Your Story (Spanish language online community also available)
  Virtual community for parents with a baby in a neonatal intensive care unit.
• Preterm Labor
  More information about signs of preterm labor, and includes common questions and answers.