The Online Encyclopedia and Dictionary






Premature birth

Premature birth (also known as preterm birth) is defined medically as birth occurring earlier than 37 completed weeks of gestation. Most pregnancies last about 40 weeks. Premature babies are sometimes called preemies. About 12 percent of babies in the United States -- or 1 in 8 -- are born prematurely each year. In 2002, more than 480,000 babies in the U.S. were born prematurely. The shorter the term of pregnancy is, the greater the risks of complications. Infants born prematurely have an increased risk of death in the first year of life. They are also at a greater risk for developing serious health problems such as: cerebral palsy, chronic lung disease, gastrointestinal problems, mental retardation, vision and hearing loss.

Although there are several known risk factors for prematurity (see below) nearly half of all premature births have no known cause. When conditions permit, doctors may attempt to stop premature labor, so that the pregnancy can have a chance to continue to full term, thereby increasing the baby's chances of health and survival. However, there is currently no reliable means to stop or prevent preterm labor in all cases.

After being born, a premature baby will cared for in a special section of the hospital known as the NICU (Neonatal Intensive Care Unit). The physicians who specialize in the care of very sick or premature babies are known as neonatologists. In the NICU, babies are kept in incubators, a bassinet enclosed in plastic with climate control equipment designed to keep babies warm and limit their exposure to germs. In some cases, an oxygen-enriched atmosphere may be used, though this is avoided where possible as it can cause damaging side effects. Premature babies may be released from the hospital when they no longer need the constant hospital care the NICU provides.



There are many known factors related to premature births. However, the nature of the relationship between these factors and premature births are unclear.

  • A woman's previous history of preterm birth, or pregnancies that ended in miscarriage.
  • Multiple pregnancies (twins, triplets, etc.) are at a higher risk for premature birth.
  • Uterine or cervical abnormalities.
  • Certain chronic disease such as high blood pressure, kidney disease and diabetes.
  • Infections of the cervix, uterus or urinary tract. Certain STDs, Beta Strep .
  • Substance abuse of tobacco, alcohol and other drugs.
  • Women who have tried to conceive for more than a year before getting pregnant are at a higher risk for premature birth. A recent study done by Dr. Olga Basso of the University of Aarhus in Denmark and Dr. Donna Baird of the U.S. National Institute of Environmental Health Sciences suggests that women who had difficulty conceiving were about 40 percent higher risk of preterm birth than those who had conceived easily.
  • Women 18 and under or over 35 are at a higher risk for premature birth.
  • Inadequate nutrition during pregnancy.
  • Antepartum hemorrhage
  • Pre-eclampsia

Symptoms and indications

The following symptoms may indicate a possible premature birth:

  • 4 or more uterine contractions in one hour, before 37 weeks' gestation.
  • A watery discharge from the vagina which may indicate premature rupture of the membranes surrounding the baby.
  • Pressure in the pelvis or the sensation that the baby has "dropped".
  • Menstrual cramps or abdominal pain.
  • Pain or rhythmic tightening in lower abdomen or back.
  • Vaginal spotting or bleeding.

Treatments For Premature Birth

Among the treatments that may be given to a woman in premature labor are:

  • Anti-contraction medications (tocolytics), such as ritodrine , fenoterol , nifedipine and the new atosiban
  • Corticosteroids - to help stimulate the growth of the fetus's lungs, which may be underdeveloped.


Possible delivery measures include:

Treatment Measures for a Premature Infant

See also

External links


  • Prematurity
  • "As your baby grows From Conception to Birth" Published by American Baby
  • March of Dimes Web site: [1]

Last updated: 05-23-2005 14:04:35