Pinky Ronen, M.D.
“Preterm labor” is labor that starts before 37 weeks of pregnancy (3 or more weeks before the woman’s due date). Pregnancy normally lasts about 40 weeks, counting from the first day of the woman’s last period. Going into labor before 37 weeks of pregnancy can be dangerous, because babies who are born preterm can have serious health problems.
What causes preterm labor? — It is often hard to know why a woman has preterm labor.
Some things that may cause preterm labor are:
It is usually not possible to tell who will go into labor early. Black women are more likely to give birth early than white, Latino, or Asian women.
Women at highest risk of preterm birth (having a baby 3 or more weeks before the due date) are:
Other problems that might increase the risk of preterm birth are:
The symptoms of preterm labor are the same as with normal labor:
Tightening of the uterus, also called “contractions.” These can make the belly feel hard while they are happening. They eventually become painful.
A change in the fluid that comes out of the vagina (it might be watery, thick, or bloody)
Pain or pressure low in the belly or in thighs
Pain in the low back
Belly cramps, sometimes with diarrhea
“Broken water,” which feels like a trickle or gush of fluid from the vagina
Some women have “Braxton Hicks contractions.” These are contractions that happen several minutes apart. They are usually not too painful and don’t get stronger or more frequent over time. They often go away when you lie down or rest. Braxton Hicks contractions are sometimes called “false labor contractions.” That’s because they don’t really mean that you are going into labor.
Yes. If you think you might be in labor, call your doctor, nurse, or midwife. You should also call if you have blood or fluid leaking from your vagina, or if you have more than 6 contractions in 1 hour. (That means that contractions are 10 minutes apart.) It is hard to know if you are actually in labor without being seen by a doctor or nurse.
Your doctor or nurse will be able to tell if you are in labor by looking at your cervix and checking to see how often your contractions are happening. There are also tests your doctor or nurse can do to find out what is going on. It might take an hour or two to figure out whether you are in preterm labor.
Not always. Some women who have preterm labor end up having their baby at the normal time.
Sometimes, the doctor or nurse will decide that it is better for the baby to be born early than to try to stop the labor. What is right for you will depend on your individual situation.
How is preterm labor treated? — There are different treatments for preterm labor. The right treatment for you will depend on:
Your doctor might give you medicine to try to stop or slow down your labor. These medicines are called “tocolytic agents.” If you are less than 34 weeks pregnant, your doctor might also give you medicines called steroids. These medicines will speed up the growth of your baby’s lungs. This will help the baby to breathe if he or she is born early. (The steroids used here are not the same as the steroids that athletes take to build muscle.)
Medicines used to stop preterm labor do not always work. If you do end up giving birth early, your healthcare team can take steps to protect the health of the baby.
There is no way to prevent preterm labor most of the time. If you had a preterm birth before, your doctor might give you a hormone (progesterone) to decrease the chance of it happening again. It is important to pay attention to how you are feeling during pregnancy. Call your doctor or nurse right away if you think you might be in labor