What Is Preterm Labor and How to Prevent It

Let’s discuss exactly what preterm labor is, how to know if you’re at risk, and what symptoms to watch out for. Finally, we’ll delve into whether there are steps you can take to reduce your risk of experiencing preterm labor.

Estimated reading time: 6 minutes

What is Preterm Labor?

First, let’s address the terminology. You’ve likely heard the words preterm and premature, and wonder if they mean the same thing. The answer is yes, the words can be used interchangeably, but we’ll use the word preterm here. So, what exactly is preterm labor? It’s when regular contractions result in the opening of your cervix between week 20 and week 37 of pregnancy (1).

Preterm Labor vs Preterm Birth

Experiencing preterm labor doesn’t necessarily mean that you’ll have a preterm birth, only that you need to seek medical attention. If that preterm labor does result in an early birth, it may be termed preterm birth or premature birth.

An average pregnancy lasts 40 weeks from the first day of your last menstrual period to your estimated due date. According to the American College of Obstetricians and Gynecologists, term birth are defined as follows (5):

  • Very Preterm: Born 28 to 32 weeks
  • Preterm: Born 32 to 37 weeks
  • Early term: Born 37 through 38 weeks
  • Full term: Born 39 through 40 weeks
  • Late term: Born 41 through 41 6/7 weeks
  • Postterm: Born 42 weeks and beyond

What are the Risks of Preterm Labor?

The biggest risk of a preterm labor is that you will experience a preterm birth. Preterm babies have not had as much time in the womb for their organ systems to develop. As a result, they’re more likely to have problems with their brain, heart, eyes, and especially their respiratory system. Preterm babies are also more likely to spend time in the NICU and to have long-term disabilities (6).

Who Is At Risk for Preterm Labor?

No one knows for sure why labor sometimes starts early. It could happen to anyone, in any pregnancy. However, we do know that certain factors increase your chances of preterm labor. Remember, while some women with these risk factors deliver early, many don’t. All pregnant women should be aware of the symptoms, which we’ll discuss below.

Risk Factors:

There’s a fairly extensive list of risk factors for preterm labor, including:

  • Having preterm labor or preterm birth with a past pregnancy
  • Being pregnant with more than one baby
  • Current infection of the vagina, amniotic membranes, bladder, or mouth
  • Bleeding in mid-pregnancy
  • Placenta previa (a placenta that is lying low, across the cervix)
  • High blood pressure
  • Having chronic illness
  • Too much amniotic fluid
  • Disease or birth defects in the baby
  • A shortened cervix
  • Problems with the uterus or placenta
  • Abnormally shaped uterus
  • Previous uterine or cervical surgery
  • Being obese or extremely underweight before pregnancy
  • Poor nutrition before or during pregnancy
  • Being older than thirty-five or younger than sixteen
  • Smoking or drug use
  • Not getting prenatal care (1, 2, 3)

What Are the Signs of Preterm Labor?

If you do experience preterm labor, it’s important that you take steps to try to stop it as soon as possible. For that reason, you should call your doctor or midwife right away if you have any of the following signs and symptoms of preterm labor before 37 weeks:

  • Change in your vaginal discharge (watery, mucus-like or bloody)
  • Notable increase in amount of vaginal discharge
  • Pressure in your pelvis or lower belly, like your baby is pushing down
  • Constant low, dull backache
  • Belly cramps with or without diarrhea
  • Regular or frequent contractions that make your belly tighten like a fist (eight or more an hour); the contractions may or may not be painful.
  • Your water breaks, either a gush or a trickle (1, 2, 3, 4)

Can I Prevent Preterm Labor?

Unfortunately, there’s no certain way to prevent the possibility of preterm labor. However, there are things you can do to decrease the risk:

  • Go to all prenatal appointments, and carefully consider suggestions from your healthcare provider
  • Continue treatment for chronic conditions
  • Eat a healthy diet; try to reach your suggested weight before pregnancy and practice sound principles to have a healthy weight gain during pregnancy
  • Get screened for infections and have them treated
  • Don’t smoke, drink alcohol, or use drugs
  • Limit strenuous activities if you’ve been having contractions; ask others for help when you need it
  • Decrease job and life stresses as much as possible (1, 3)

What If I Go Into Preterm Labor?

If you go into labor before 37 weeks, your provider may attempt to postpone birth so that your baby has extra time to grow and mature. Even if they’re not able to stop labor altogether, if you can slow it down, you buy your baby more precious time in the womb. Even a few extra days can mean a healthier baby (2). During that time, your baby may receive medications aimed to speed up the development of the lungs and to improve his or her health. (3)

Common Recommendations:

If you do experience preterm labor, your doctor may recommend one of the following:

  • Bed rest. This can mean a range of things. You may have to stay in bed at all times except when absolutely necessary, such as to go to the bathroom. Or it may mean a decrease in your normal daily activities.
  • Uterine monitoring. If hospitalized, your contractions will be electronically monitored. If you’re at home, your caregiver will ask you to keep track of contractions.
  • Pelvic rest. This means restricting sexual activity. Contractions can be caused by orgasm, the prostaglandins in semen, and nipple stimulation.
  • Medication. There are drugs that can relax the uterus. They don’t often stop labor, but may delay birth, buying more time inside for baby.

The Takeaway

The best shot your baby has for health and safety is to stay inside the womb until at least the 37th week. Preterm labor can lead to preterm birth, so know the signs, and communicate with your doctor or midwife if you have any symptoms of preterm labor.

Kopa Birth’s online birthing classes allow you to prepare for a natural hospital birth from the comfort of your own home, 24/7. Enroll today in our free online childbirth class and start preparing for your natural birth!


  1. Preterm labor. (2019, December 24). Retrieved August 24, 2020, from https://www.mayoclinic.org/diseases-conditions/preterm-labor/symptoms-causes/syc-20376842
  2. American College of Obstetricians and Gynecologists. (2021). YOUR PREGNANCY AND CHILDBIRTH: Month to month.
  3. Simkin, P., Whalley, J., Keppler, A., Durham, J., & Bolding, A. (2018). Pregnancy, childbirth, and the newborn: The complete guide. New York, NY: Da Capo Lifelong.
  4. Signs and symptoms of preterm labor. (n.d.). Retrieved August 24, 2020, from https://www.marchofdimes.org/complications/signs-and-symptoms-of-preterm-labor.aspx
  5. Spong CY. Defining “term” pregnancy: recommendations from the Defining “Term” Pregnancy Workgroup. JAMA 2013;309:2445–6.
  6. March of Dimes. (2019). Premature Babies. Retrieved from https://www.marchofdimes.org/complications/premature-babies.aspx?gclid=Cj0KCQiAnb79BRDgARIsAOVbhRqhO8QspQu9SZaYV5oI937vz5IWtyp8nA7j10VrUk-rFUhx3XIV5l0aAutsEALw_wcB

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Meet Katie Griffin

I’m a registered nurse, Lamaze certified childbirth educator, and the mother of 7. I help women realize their dream of a natural, intimate, and empowering hospital birth.

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Let’s discuss exactly what preterm labor is, how to know if you’re at risk, and what symptoms to watch out for. Finally, we’ll delve into whether there are steps you