Are You at Risk?
Three groups of women are most at risk of developing preterm labor: those who are pregnant with multiples, those who have given birth prematurely in the past, and those who have certain problems with their uterus (such as an abnormally shaped uterus with reduced room for fetal growth) or cervix (such as a weak, sometimes called "incompetent," cervix, which tends to open too early in pregnancy).
Other factors may also increase the risk of preterm labor, though they are less common than those already mentioned. Women who receive late or no prenatal care, who become pregnant with a single fetus from in vitro fertilization, or who wait a short time -- less than nine months -- between pregnancies may also be at increased risk of preterm labor. African-American women and women younger than 17 or older than 35 are also at increased risk, though the reasons why are not well understood.