What Happens
If
preterm labor occurs close to your due date (in the
35th or 36th week of pregnancy), you may be allowed to deliver without delay.
Preterm birth at this point in a pregnancy usually results in few or no serious
complications.
Symptoms of preterm labor are a warning sign. They do
not necessarily mean that preterm birth is inevitable. Of all women who see a
health professional about their preterm contractions (before 37 weeks, without
preterm premature rupture of membranes (pPROM), about
half will deliver at full term.4
If preterm labor contractions do not stop, the
cervix may thin (efface) and open (dilate). The
amniotic sac may break (rupture), leading to preterm
birth.
The method of delivery used in premature labor depends on the
health of the mother and fetus. In most cases a woman can deliver vaginally. If
the health of the mother or fetus is at risk, a
cesarean section may be needed. See the topic
Pregnancy for more information.
Sometimes a pregnancy poses a great enough health risk to a mother
or her fetus that it is necessary to deliver by
cesarean or induce labor for a preterm vaginal
delivery. This is called an indicated preterm birth, accounting for about 25%
of preterm births.5
Premature infant
The more prematurely an infant is born, the greater the risk of
medical complications of prematurity. A premature
fetus's likelihood of survival increases as the pregnancy advances and as the
fetus gains weight. The fetus's stage of development, ability to breathe (lung
maturity), and overall health are also important factors for survival. Because
of advances in medical care, more premature infants are surviving today than in
years past. For more information, see the topic
Premature Infant.