Preterm labour

Premature Labor

Preterm labour

Pregnancy is normally a time of happiness and anticipation, but it can also be a time of uncertainty.

Many women have concerns about what is happening with their baby and wonder “Is everything okay”? Some women have concerns about going into labor early. Premature labor occurs in about 12% of all pregnancies.

However, by knowing the symptoms and avoiding particular risk factors, a woman can reduce her chance of going into labor prematurely.

What is premature labor?

A normal pregnancy lasts about 40 weeks. Occasionally, labor begins prematurely, before the 37th week of pregnancy. This happens because uterine contractions cause the cervix to open earlier than normal. Consequently, the baby is born premature and can be at risk for health problems.

Fortunately, research, technology, and medicine have helped improve the health of premature babies.

What risk factors place me at high risk for premature labor?

Although the specific causes of premature labor are not yet known, certain factors may increase a woman’s risk of having premature labor. However, having a specific risk factor does not mean a woman will experience premature labor. A woman might have premature labor for no apparent reason.

If you have any of the following risk factors, it is important to know the symptoms of premature labor and what to do if it occurs:

Women are at greatest risk for premature labor if:

  • They are pregnant with multiples
  • They have had a previous premature birth
  • They have certain uterine or cervical abnormalities

Medical risk factors include:

Lifestyle risks for premature labor include:

What are the warning signs and symptoms?

It may be possible to prevent premature birth by knowing the warning signs and calling your health care provider if you think you might be having premature labor.

Warning signs and symptoms of premature labor include:

  • Five or more uterine contractions in an hour
  • Watery fluid leaking from your vagina (this could indicate that your water has broken)
  • Menstrual- cramps in the lower abdomen that can come and go or be constant
  • Low, dull backache felt below the waistline that may come and go or be constant
  • Pelvic pressure that feels your baby is pushing down
  • Abdominal cramps that may occur with or without diarrhea
  • Increase or change in vaginal discharge

What does a contraction feel ?

As the muscles of your uterus contract, you will feel your abdomen harden. As the contraction goes away, your uterus becomes soft. Throughout pregnancy, the layers of your uterus will tighten irregularly, which is usually not painful.

These are known as Braxton-Hicks contractions; they are usually irregular and do not open the cervix. If these contractions become regular or more frequent, such as one every 10-12 minutes for at least an hour, they may be premature labor contractions which can cause the cervix to open.

If this happens, it is important to contact your health care provider as soon as possible.

How can I check for contractions?

While lying down, use your fingertips to feel your uterus tighten and soften. This is called “palpation.” During a contraction, your abdomen will feel hard all over, not just in one area. However, as your baby grows you may feel your abdomen become firmer in one area and then become soft again.

What should I do if I think I am experiencing premature labor?

If you think you are showing signs and symptoms of premature labor call your health care provider immediately.

It is natural to be a bit anxious during this time, but by becoming aware of the symptoms and taking the following steps, you can help prevent premature labor:

  • Empty your bladder.
  • Lie down tilted towards your left side; this may slow down or stop signs and symptoms.
  • Avoid lying flat on your back; this may cause contractions to increase.
  • Drink several glasses of water, because dehydration can cause contractions.
  • Monitor contractions for one hour by counting the minutes from the beginning of one contraction to the beginning to the next.

If symptoms worsen or don’t disappear after one hour, call your health care provider again or go to the hospital. When you call your health care provider, be sure to tell them that you are concerned that you might have started premature labor.

The only sure way to know if you are in premature labor is by examination of your cervix. If your cervix is opening up, premature labor could be the cause.

What is the treatment to prevent premature labor from starting or continuing?

  • Magnesium Sulfate is a medication given through an IV, which may cause nausea temporarily. A large dose is given initially and then a smaller continuous dose is given for 12-24 hours or more.
  • Corticosteroid is a medication given 24 hours before birth to help accelerate the baby’s lung and brain maturity.
  • Oral medications are sometimes used to decrease the frequency of contractions and may make women feel better.

What impact does premature labor have on my pregnancy?

The longer your baby is in the womb, the better the chance he or she will be healthy. Babies who are born prematurely are at higher risk of brain and other neurological complications, as well as breathing and digestive problems.

Some premature babies grow up with a developmental delay and/or have learning difficulties in school. The earlier in pregnancy a baby is born, the more health problems are ly to develop.

Premature labor does not always result in premature delivery. Some women with premature labor and early dilation of the cervix are put on bed rest until the pregnancy progresses. Most babies born prior to 24 weeks have little chance of survival.

Only about 50% will survive and the other 50% may die or have permanent problems. However, babies born after 32 weeks have a very high survival rate and usually do not have long term complications. Premature babies born in hospitals with neonatal intensive care units (NICU) have the best results.

If you deliver at a hospital that does not have a NICU, you might be transferred to a nearby hospital.

Last updated: October 13, 2019 at 15:31 pm

Compiled using information from the following sources:

1. March of Dimes

2. eMedicine

3. William’s Obstetrics Twenty-Second Ed. Cunningham, F. Gary, et al, Ch. 36.


Preterm labor and premature birth: Are you at risk?

Preterm labour

  • Preterm labor and premature birth happen too early, before 37 weeks of pregnancy.

  • Babies born prematurely are more ly to have health problems than babies born on time.

  • Learn the signs and symptoms of preterm labor so you can get help quickly if they happen to you.

  • We don’t always know what causes preterm labor and premature birth. We do know certain risk factors may make you more ly to give birth early.

  • Talk to your provider about what you can do to help reduce your risk for preterm labor and premature birth.

Preterm and premature mean the same thing — early. Preterm labor is labor that begins early, before 37 weeks of pregnancy. Labor is the process your body goes through to give birth to your baby.

Preterm labor can lead to premature birth. Premature birth is when your baby is born early, before 37 weeks of pregnancy. Your baby needs about 40 weeks in the womb to grow and develop before birth.


Babies born before 37 weeks of pregnancy are called premature. Premature babies can have serious health problems at birth and later in life. About 1 in 10 babies is born prematurely each year in the United States. 

What are the signs and symptoms of preterm labor? 

Signs of a condition are things someone else can see or know about you, you have a rash or you’re coughing. Symptoms are things you feel yourself that others can’t see, having a sore throat or feeling dizzy. Learn the signs and symptoms of preterm labor so you can get help quickly if they happen to you.

If you have even one of these signs and symptoms of preterm labor, call your provider right away:

  • Change in your vaginal discharge (watery, mucus or bloody) or more vaginal discharge than usual
  • Pressure in your pelvis or lower belly, your baby is pushing down
  • Constant low, dull backache
  • Belly cramps with or without diarrhea
  • Regular or frequent contractions that make your belly tighten a fist. The contractions may or may not be painful.
  • Your water breaks

When you see your provider, he may do a pelvic exam or a transvaginal ultrasound to see if your cervix has started to thin out and open for labor. Your cervix is the opening to the uterus (womb) that sits at the top of the vagina (birth canal).

A transvaginal ultrasound is done in the vagina instead of on the outside of your belly. a regular ultrasound, it uses sound waves and a computer to make a picture of your baby. If you’re having contractions, your provider monitors them to see how strong and far apart they are.

You may get other tests to help your provider find out if you really are in labor.

If you’re having preterm labor, your provider may give you treatment to help stop it. Or you may get treatment to help improve your baby’s health before birth. Talk to your provider about which treatments may be right for you. 

Are you at risk for preterm labor and premature birth?

We don’t always know for sure what causes preterm labor and premature birth. Sometimes labor starts on its own without warning. Even if you do everything right during pregnancy, you can still give birth early. 

We do know some things may make you more ly than others to have preterm labor and premature birth. These are called risk factors. Having a risk factor doesn’t mean for sure that you’ll have preterm labor or give birth early. But it may increase your chances. Talk to your health care provider about what you can do to help reduce your risk.

Because many premature babies are born with low birthweight, many risk factors for preterm labor and premature birth are the same as for having a low-birthweight baby. Low birthweight is when a baby is born weighing less than 5 pounds, 8 ounces.

These three risk factors make you most ly to have preterm labor and give birth early:

Medical risk factors before pregnancy for preterm labor and premature birth

  • Being underweight or overweight before pregnancy. This can include having an eating disorder, anorexia or bulimia.
  • Having a family history of premature birth. This means someone in your family ( your mother, grandmother or sister) has had a premature baby. If you were born prematurely, you’re more ly than others to give birth early.  
  • Getting pregnant again too soon after having a baby. For most women it’s best to wait at least 18 months before getting pregnant again. Talk to your provider about the right amount of time for you. 

Medical risk factors during pregnancy for preterm labor and premature birth

Having certain health conditions during pregnancy can increase your risk for preterm labor and premature birth, including:

  • Connective tissue disorders, Ehlers-Danlos syndromes (also called EDS) and vascular Ehlers-Danlos syndrome (also called vEDS). Connective tissue is tissue that surrounds and supports other tissues and organs. EDS can cause joints to be loose and easy to dislocate; skin to be thin and easily stretched and bruised; and blood vessels to be fragile and small. It also can affect your uterus and intestines. vEDS is the most serious kind of EDS because it can cause arteries and organs ( the uterus) to rupture (burst). EDS and vEDS are genetic conditions that can be passed from parent to child through genes. 
  • Diabetes. Diabetes is when your body has too much sugar (called glucose) in your blood. 
  • High blood pressure and preeclampsia. High blood pressure (also called hypertension) is when the force of blood against the walls of the blood vessels is too high. This can stress your heart and cause problems during pregnancy. Preeclampsia is a kind of high blood pressure some women during or right after pregnancy. If not treated, it can cause serious problems and even death.
  • Infections, including sexually transmitted infections (also called STIs) and infections of the uterus, urinary tract or vagina
  • Intrahepatic cholestasis of pregnancy (also called ICP). This is the most common liver condition that happens during pregnancy.
  • Thrombophilias. These are conditions that increase your risk of making abnormal blood clots. 

Other medical risk factors during pregnancy include:  

  • Getting late or no prenatal care. Prenatal care is medical care you get during pregnancy. 
  • Not gaining enough weight during pregnancy. This can include having an eating disorder, anorexia or bulimia.
  • Bleeding from the vagina in the second or third trimester  
  • Preterm premature rupture of the membranes (also called PPROM). Premature rupture of membranes (also called PROM) is when the amniotic sac around your baby breaks (your water breaks) before labor starts. PPROM is when this happens before 37 weeks of pregnancy. If you have any fluid leaking from your vagina, call your provider and go to the hospital.  
  • Being pregnant after in vitro fertilization (also called IVF). IVF is a fertility treatment used to help women get pregnant.   
  • Being pregnant with a baby who has certain birth defects, heart defects or spina bifida. Birth defects are health conditions that are present at birth. They change the shape or function of one or more parts of the body. Birth defects can cause problems in overall health, how the body develops or how the body works. Spina bifida is a birth defect of the spine.

Risk factors in your everyday life for preterm labor and premature birth

  • Smoking, drinking alcohol, using street drugs or abusing prescription drugs 
  • Having a lot of stress in your life.
  • Low socioeconomic status (also called SES). SES is a combination of things your education, your job and your income (how much money you make).   
  • Domestic violence. This is when your partner hurts or abuses you. It includes physical, sexual and emotional abuse.  
  • Working long hours or having to stand a lot 
  • Exposure to air pollution, lead, radiation and chemicals in things paint, plastics and secondhand smoke. Secondhand smoke is smoke from someone else’s cigarette, cigar or pipe. 

Age and race as risk factors for preterm labor and premature birth

Being younger than 17 or older than 35 makes you more ly than other women to give birth early. In the United States, black women are more ly to give birth early. Almost 17 percent of black babies are born prematurely each year.

Just more than 10 percent of American Indian/Alaska Native and Hispanic babies are born early, and less than 10 percent of white and Asian babies.

We don’t know why race plays a role in premature birth; researchers are working to learn more about it.   

Can you reduce your risk for preterm labor and premature birth?

Yes, you may be able to reduce your risk for early labor and birth. Some risk factors are things you can’t change, having a premature birth in a previous pregnancy. Others are things you can do something about, quitting smoking. 

Here’s what you can do to reduce your risk for preterm labor and premature birth:

  • Get to a healthy weight before pregnancy and gain the right amount of weight during pregnancy. Talk to your provider about the right amount of weight for you before and during pregnancy.
  • Don’t smoke, drink alcohol use street drugs or abuse prescription drugs. Ask your provider about programs that can help you quit. 
  • Go to your first prenatal care checkup as soon as you think you’re pregnant. During pregnancy, go to all your prenatal care checkups, even if you’re feeling fine. Prenatal care helps your provider make sure you and your baby are healthy.  
  • Get treated for chronic health conditions, high blood pressure, diabetes, depression and thyroid problems. Depression is a medical condition in which strong feelings of sadness last for a long time and interfere with your daily life. It needs treatment to get better. The thyroid is a gland in your neck that makes hormones that help your body store and use energy from food. 
  • Protect yourself from infections. Talk to your provider about vaccinations that can help protect you from certain infections. Wash your hands with soap and water after using the bathroom or blowing your nose. Don’t eat raw meat, fish or eggs. Have safe sex. Don’t touch cat poop. 
  • Reduce your stress. Eat healthy foods and do something active every day. Ask family and friends for help around the house or taking care of other children. Get help if your partner abuses you. Talk to your boss about how to lower your stress at work. 
  • Wait at least 18 months between giving birth and getting pregnant again. Use birth control until you’re ready to get pregnant again. If you’re older than 35 or you’ve had a miscarriage or stillbirth, talk to your provider about how long to wait between pregnancies. Miscarriage is the death of a baby in the womb before 20 weeks of pregnancy. Stillbirth is the death of a baby in the womb after 20 weeks of pregnancy.   

Last reviewed: March, 2018

See also: Signs and symptoms of preterm labor infographic