Preterm Labour

What is Preterm Labour  

Preterm labour is when labour starts before the end of the 37th week of pregnancy.  

Pregnancy lasts an average of 40 weeks (usually between 38 and 42 weeks). A premature birth is when a baby is born before 37 weeks. So, a baby born at 36 weeks and 6 days is officially premature. 

The degree of prematurity is often described by gestational age as: 

• extremely premature – from 22-28 weeks 
• very premature – 28-32 weeks 
• moderately premature – 32-34 weeks 
• late preterm – 34-37 weeks. 

However, about 8% of babies will be born before 37 weeks. Symptoms of preterm labour may not mean you are about to give birth. Only about 50% of women with symptoms will give birth within 7-10 days. (Department of Health and Wellbeing, Government of South Australia 2020) 

If preterm labour symptoms are identified and treated early, it may be possible to prevent a preterm birth. 

Why is preterm birth a concern?  

Preterm babies may be very small and may not have finished developing. They may need the intensive care and artificial support systems of a special hospital nursery - often for a long time, until they can breathe on their own, feed well, and regulate their own body temperature. Even with this intensive care, complications of preterm birth are the most serious threat to the life and health of newborn babies. If you are at risk of having a preterm baby, you and your support person will meet the Neonatologist to discuss the risks for your baby. You will be given time to ask any questions you have. You and your support person will also be able to visit the nursery to meet the neonatal team and see the area where your baby will be. 

Who is more likely to go into preterm labour?  

Any woman can have preterm labour, however, it is more likely if you have:  

• had preterm births before – the likelihood increases with each birth  
• stress, poor diet, poor living conditions  
• poor dental care 
• infections, e.g. urinary tract  
• smoked or used drugs or alcohol during pregnancy  
• a multiple pregnancy (twins or more).

How is Preterm Labour checked? 

You will be examined and may be recommended to have:  

• monitoring of your baby’s heart - usually with a cardiotocograph (CTG) machine  
• observation and monitoring of your contractions  
• a speculum examination to see if your cervix is opening and/or if your waters have broken.  
• A fetal fibronectin test -this test is done by taking a swab from around your cervix to test for a protein called fetal fibronectin. The presence of this protein is linked to preterm birth. 
• an ultrasound to measure the length of your cervix. This might be done by gently placing a ultrasound probe, into your vagina, or a transducer may be gently placed on your abdomen. If the measurement shows that your cervix has started to shorten this usually means you are more likely to have a preterm birth.