Preterm birth refers to a baby born more than 4 weeks early. It is also called premature birth. About 10% of all babies are born more than 4 weeks early. Preterm delivery of a baby can be dangerous because the baby's lungs and other organ systems may not be ready to function on their own.
In most cases, the cause of premature labor is unknown. Causes we do understand include:
 | a uterus with an abnormal shape |
| a large uterus (such as with multiple fetuses) |
| hydramnios (excessive amniotic fluid) |
| an abnormal placenta |
| premature rupture of the membranes |
| incompetent cervix (a weak cervix that dilates very early) |
| abnormalities of the fetus |
| fetal death |
| retained IUD |
| maternal illness, such as high blood pressure, or some maternal infections |
| incorrect estimate of gestational age, which means the baby is really not premature |
It is important to try to halt the contractions if you go into labor too early. Your doctor may have special advice for you. Most doctors start by recommending bed rest and increased fluids to stop labor.
Bed rest means lying in bed on your side. Either side is OK, but the left side is best. You may have to lie in bed for a simple reason: It works. Bed rest may mean you have to modify or to stop your activities, but we have found that it helps end premature labor.
Before we had medications, bed rest was the only treatment for premature labor.
Medication
Medications that relax the uterus and decrease contractions include:
| magnesium sulfate, which is usually given through an I. V.; |
sometimes it is given orally
| beta-adrenergics, including ritodrine and terbutaline, which are given orally, through an I. V. or by injection |
| sedatives or narcotics, which may be used in early attempts to stop premature labor |
Even if you take medication, you will probably be advised to rest in bed. Bed rest is an essential part of the treatment plan for premature labor.
It is better for both mother and baby if premature labor is stopped. Premature delivery increases the possibility of fetal problems and maternal problems, such as an increased risk of C-section.
