Preterm labour

What is preterm labour?

Preterm labour is the presence of regular contractions that lead to changes in the cervix prior to term (37 weeks). This may lead to the birth of the baby. Preterm delivery is categorized as follows:

Extremely preterm (less than 28 weeks)
Very preterm (28-32 weeks)
Moderate to late preterm (32 to 37 weeks)

Preterm tightenings of the uterus are common and not all will lead to preterm birth. Braxton Hicks contractions, where you experience irregular, mild contractions, are “practice” or “warm-up” contractions and do not change the cervix or lead to the delivery of the baby. However, it is very important to go to the hospital if you have regular contractions at any time before 37 weeks that don’t go away when you change your activity. There are some important things your medical team can do to help prevent some of the complications associated with preterm birth, but they have to be done early to be most effective. Click here for a helpful guide to discerning the difference between Braxton-Hicks and preterm labour contractions so you know when to contact your care provider: Braxton-Hick vs Contractions.

Why is preterm labour and birth a concern?

Preterm birth occurs in approximately 10% of pregnancies. Premature babies are more vulnerable to certain health challenges, and the earlier in a pregnancy a baby is born the more care they will need once they are born. Medical care of preterm babies has improved dramatically over the past several decades. However, if a baby is born prematurely parents should expect that they will need to stay in the hospital until at least their anticipated due date, as they will need specialized care while they finish the growth and development they should have done in the womb.

What causes preterm birth?

In about half of all preterm births, the reason is unknown; the mothers and infants were otherwise healthy. However, there are some factors that are known to increase the risk of going into labour early. Here are some of the known risk factors for preterm labour and how to reduce them:

Smoking. It is best not to smoke during pregnancy. Your baby can still benefit if you quit smoking during your pregnancy. See here for information on smoking in pregnancy.
Working too hard. Working long hours, doing strenuous work, and being tired all the time can lead to a preterm birth. Speak with your employer to try to reduce strenuous work.
Physical and emotional abuse. When someone hurts you, they can also hurt your unborn baby. Even non-physical forms of abuse like psychological abuse can lead to a preterm birth by significantly raising your stress levels. If you are experiencing abuse within your household or relationship, a family crisis centre in your area can offer help and support.
Cervical insufficiency. This is a rare condition in which the cervix (the lower part of the uterus) dilates or “opens” early and is associated with premature birth. This can sometimes be diagnosed during a vaginal examination or by measuring the size of the cervix during an ultrasound. Sometimes this can be treated with progesterone supplements or with a “cerclage”- closing the cervix with sutures and removing them when the baby is full term.
Bladder, vaginal or uterine infections. You may have a bladder or kidney infection if you have pain when you urinate, if you have to go often, and if when you do only a small amount of urine comes out. You may have an infection in your vagina or cervix if you notice an unusual vaginal discharge, have pain in your pelvis or groin area, or a fever. Notify your care provider.
Being very overweight or underweight. Treatment depends on the cause. Sometimes this problem is helped by eating healthy, good food on a regular basis. Talk to your care provider if you are underweight and having difficulty eating sufficient calories during pregnancy.
Placenta previa. This is a condition in which the placenta implanted and grew over the opening of the cervix (through which the baby is born). This can lead to hemorrhaging (excessive bleeding) during labour. This is usually found during a routine ultrasound. The baby is usually delivered by Caesarean section before labour has a chance to begin.
Preterm premature rupture of membranes. This occurs when the sac of amniotic fluid (your “water”) breaks or leaks before your baby reaches full term. This may be caused by an infection, or may not have a known cause. If your water breaks early, treatment depends on how much amniotic fluid is lost and how close to your due date you are. Contact your health care provider right away if your water breaks.
Health conditions (gestational hypertension, diabetes). Some conditions (diabetes, high blood pressure) may be less manageable during the pregnancy and in some situations the only way to manage them is to deliver the baby. Sometimes the labour will begin too early on its own and in other cases the labour needs to be brought on (induced).

What are the signs of preterm labour?

Contact your health care provider right away if you are having any of the following:

Backache that comes and goes
Regular contractions less than 10 minutes apart
Cramping in your lower abdomen
Fluid leaking from your vagina
Pressure in your pelvis or vagina
Vaginal bleeding