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Preterm labour is labour that begins too early—between 20 and 37 weeks of pregnancy. In labour, the uterus contracts to open the cervix. This is the first stage of childbirth. In most pregnancies, this happens at 37 to 42 weeks. Preterm labour is also called premature labour.
Preterm labour doesn't always lead to preterm birth, but it may. A baby born too early may have serious problems, such as chronic lung disease. This is because many of the baby's organs, especially the heart and lungs, aren't fully grown yet. The earlier a baby is born, the higher the risk of problems.
Preterm labour can be caused by a problem involving the baby, the mother, or both. Possible causes of preterm labour include being pregnant with more than one baby, an infection, and problems with the placenta, uterus, or cervix. Often a combination of several factors is responsible. Sometimes the cause isn't known.
It can be hard to tell when labour starts. But you may notice one or more symptoms, such as menstrual-like cramps, leaking or gushing of fluid from your vagina, or regular contractions. This means about 6 or more contractions in 1 hour, even after you've had a glass of water and are resting.
If you have symptoms of preterm labour, both you and your baby will be examined and monitored. You may have urine and blood tests to check for problems that can cause preterm labour. Your heathcare provider or registered midwife will check the baby's heartbeat and do an ultrasound to see how your baby is doing.
Preterm labour isn't always treated. When deciding whether and how to treat it, many things are considered, including your health and your baby's age, weight, and health. Your healthcare provider or registered midwife may use medicine to try to delay the birth or medicines to prevent infection and prepare your baby for birth.
Preterm labour can be caused by a problem involving the baby, the pregnant person, or both. Often a combination of several factors is responsible. Sometimes the cause isn't known.
Possible causes of preterm labour include:
It's hard to prevent preterm labour, because it usually isn't expected. Also, it's often due to causes that aren't completely understood.
But building some healthy pregnancy habits—such as going to all of your healthcare providers appointments—may help prevent preterm labour and give your baby the best chance to be healthy.
Being pregnant with twins, triplets, or more increases the chances of preterm labour and problems for the babies.
If you had preterm labour in a previous pregnancy, your risk for having it again is high. Your healthcare provider may consider giving you vaginal progesterone during your second and third trimesters. This may help lower your risk of preterm labour. This may also be used for a type of cervical change called short cervix.
It can be hard to tell when labour starts, especially when it starts early. But you may notice one or more symptoms, including:
If your contractions stop, they may have been Braxton Hicks contractions. They're like practice contractions. But sometimes it can be hard to tell the difference.
If preterm labour 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 doesn't usually cause serious problems.
But preterm labour doesn't always mean that preterm birth will happen. Your healthcare provider may be able to stop your preterm labour.
When preterm labour can't be stopped, most people can deliver vaginally. But if your health or your baby's health is at risk, you may need a caesarean section.
If a baby is born too early, the baby may have complications, such as bleeding in the brain or chronic lung disease. The earlier a baby is born, the higher the risk.
Preterm labour can be hard to recognize. Get the earliest possible medical care by calling your healthcare provider or your midwife about signs of preterm labour.
Call your healthcare provider or your midwife if:
Call your healthcare provider, your midwife, or the labour and delivery unit of your local hospital if:
If you are having painless or mild contractions that are irregular or more than 15 minutes apart:
If your contractions stop, they were probably Braxton Hicks contractions. These are harmless and normal. Braxton Hicks contractions are often irregularly timed and uncomfortable rather than painful.
Call your healthcare provider or midwife if you start to have regular contractions.
If you think you have symptoms of preterm labour, your healthcare provider or midwife can check to see if your water has broken, if you have an infection, or if your cervix is starting to dilate. You may also have urine and blood tests to check for problems that can cause preterm labour.
Your healthcare provider or midwife will check the baby's heartbeat and do an ultrasound to see how your baby is doing.
Preterm labour isn't always treated. When deciding whether and how to treat it, many things are considered, including your health and your baby's age, weight, and health.
If you are in preterm labour, your healthcare provider or midwife must compare the risks of early delivery with the risks of waiting to deliver. Depending on your situation, your healthcare provider or midwife may:
Symptoms of preterm labour are warning signs. They don't necessarily mean that you'll have a preterm birth.
If you're less than 37 weeks pregnant and you're having more or stronger contractions than usual, try these things.
Not having enough liquids can cause contractions.
If your contractions get worse during the hour, call your healthcare provider or midwife, or go to the hospital.
Although stress isn't thought to be a direct cause of preterm labour, try to do less, ask for help, and eat well.
Follow your healthcare provider’s instruction about how often to count your baby’s movements. For information on counting your baby’s movements, go to: Fetal Movement Count Chart
If your contractions are causing changes in your cervix, or if you have signs of infection or preterm prelabour rupture of membranes (pPROM), you may be given medicines to help delay delivery.
Delaying labour even for a short time can allow you to be:
Medicines that may be used to treat preterm labour include:
Certain tocolytic medicines can be dangerous when a fetus is showing signs of distress or for people with certain health conditions (such as heart problems, severe pre-eclampsia, or poorly controlled diabetes or high blood pressure).
Adaptation Date: 11/1/2022
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
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