Premature labour and birth

Premature or pre-term labour is labour that starts before 37 weeks of pregnancy, or more than 3 weeks early. The earlier a baby is born, the less mature and less ready they are to live outside their mother. Due to advances in neonatal care, babies are much more likely to survive and go on to live healthy, normal lives than they were a generation ago.

There are many reasons why you may give birth before your due date; however, if you go into premature labour your doctor usually won’t know why this has happened. You are at an increased risk of having a premature birth if you:

• have already had a premature baby
• have an ultrasound scan that suggests the neck of your womb (the cervix) does not seem strong enough
• are pregnant with twins or triplets
• have had 3 or more miscarriages or terminations
• have had previous treatment to your cervix
• smoke
• are underweight or very overweight
• have poor dental hygiene
• have a medical condition such as diabetes.

If your doctor or LMC thinks you are at high risk of premature labour, you may be given a medication called progesterone to help prevent premature birth.

Some babies are born prematurely because there is a problem that puts the life of the mother or baby at risk, for example, if the baby has stopped growing inside the womb or if the mother’s blood pressure has become dangerously high. In this situation, your doctor may recommend a Caesarean section.

About 1 in 10 women will have a premature baby. This is the most common reason for a baby to spend some time in a neonatal unit. Due to advances in neonatal care, babies are much more likely to survive and go on to live healthy, normal lives than they were a generation ago.

If you have risk factors for premature birth, your doctor or LMC will refer you to a specialist. However, at least half of the women who go into premature labour will have no risk factors for early delivery, so it is important to know what the signs of premature birth are.

The earlier premature birth is recognised, the better the outlook for the baby. If you have any of the 'ABCs' of premature birth listed below you should contact your LMC straight away. Usually, an examination and assessment of you and your baby are needed. Sometimes you may need to stay in hospital for observation and treatment. 

The ABC of premature birth 

A: Abnormal vaginal discharge. Watch for vaginal discharge of water or mucus; sometimes there will be a small amount of blood. The breaking of the bag of waters around the baby can cause a gush of fluid. This is often one of the first signs of being in premature labour. 

B: Bleeding. Vaginal bleeding is never a normal part of pregnancy. A ‘show’ is mucus and blood that occurs before labour starts, and is due to the plug in the neck of the womb (the cervix) coming away as the cervix starts to open.

C: Contractions. It can be difficult to tell if contractions are labour contractions or just practice contractions, called Braxton Hicks. Braxton Hicks contractions are not usually regular and while they can be uncomfortable, they do not become progressively stronger or more painful. They can become more noticeable if you have a full bladder. Try going to the toilet – Braxton Hicks contractions may settle down if your bladder is emptied. 

Painful contractions occurring regularly every 15 minutes over a period of more than an hour may indicate the start of premature labour. To time the contractions, use your hand to feel the uterus tighten, become hard and then relax. A contraction may last from 30 seconds to around 2 minutes. Time how long it takes from the beginning of one contraction to the start of the next one. Contact your doctor or LMC if you think you are having regular contractions and could be in premature labour.

D: is for Don’t Know! Sometimes a woman just doesn’t know if what she is feeling is OK. Abdominal cramps, pelvic pressure and lower backache can mean labour is starting. Some women experience nausea and diarrhoea(external link) which can cause bowel pain and discomfort.

Once you contact your LMC, you may be asked to go to the hospital for assessment. You will be seen first by a midwife, then by a doctor who will assess whether you are in premature labour and assess the health of your baby. 

If you are in premature labour and it is more than 5 weeks before your due date, you will probably be given medication to stop or delay the labour. The delay can make time for you to be given medication to improve the maturity of your baby’s lungs in preparation for birth. The delay is also important because it will give time for transfer to a bigger hospital if necessary. It is much better to transfer a baby inside a mum than in an incubator.  

The nurses and doctors in the neonatal units around New Zealand are specially trained to look after premature babies. Most of the time you will be able to stay in the neonatal unit to be close to your baby. If you have had a Caesarean, or have a medical complication, then you will need to stay in the post-natal ward for a few days. The midwives and neonatal nurses will encourage you to breastfeed or express milk and to do as many of the things that parents of full-term babies do.

A-Z on pregnancy and keeping healthy(external link) Healthpoint NZ and Counties Manukau Health Maternity Services
What are the risk factors for preterm labor and birth?(external link) National Institute of Child Health and Human Development, US, 2013

Your pregnancy(external link) Ministry of Health NZ, 2013
Your baby's movements & what they mean [PDF, 1.8 MB] Australia & NZ Stillbirth Alliance (ANZSA), 2016. Available in the following languages: English,  [PDF, 1.8 MB] Chinese Simplified,  [PDF, 1.1 MB] Maori,  [PDF, 762 KB] Traditional Chinese [PDF, 1.3 MB]
Assisted birth(external link) RANZCOG, 2021
Caesarean section(external link) RANZCOG, 2021
Monitoring the baby's heart rate in labour(external link) RANZCOG, Australia, 2016

Pregnancy topics
Pain relief during childbirth
High blood pressure in pregnancy
Pregnancy – planning for
Pregnancy – giving your child the best start in life