What does premature birth mean?
Once you reach 37 completed weeks of pregnancy, your baby is what’s called “term”. Your baby will be premature if he arrives before you’re 37 weeks pregnant. Most premature babies arrive after 32 weeks (HES online 2012a) and have a good chance of surviving and growing up to be healthy.
Intensive care for extremely early babies has improved dramatically, and survival rates are much better than they used to be (Kyser et al 2012, RCOG 2014). However, there can sometimes be long-lasting effects for babies arriving very early, including cerebral palsy and learning difficulties (RCOG 2014).
Most babies who are relatively early, at around 34 weeks to 36 weeks, thrive and do well. However, they can be at greater risk of long-term developmental problems when compared with babies born at term (Boyle 2012, Engle and Kominariak 2008).
Generally, the further on in your pregnancy you are, the more likely it is that your baby will do well. His organs will be more mature, his lungs better prepared for breathing, and he’ll have more strength for sucking and feeding.
How common is premature birth?
In Europe as a whole, nearly eight per cent of births are premature (March of Dimes et al 2012). Most of these are only somewhat premature, rather than very early. For example, in England only two per cent of premature births happen before 32 weeks, and about one per cent before 28 weeks (HES online 2012a).
If you’re healthy and your pregnancy is going well, you’re likely to give birth when your baby is term (37 weeks to 42 weeks). Only about two per cent of women who are carrying one baby and have a healthy pregnancy go into labour early (Haas 2011).
Why does premature birth happen?
The majority of premature births happen when labour starts by itself, without the waters breaking. However, about a quarter of premature births are planned early inductions or caesareans, performed because of complications affecting either the mum or the baby.
Premature birth is much more common among pregnancies with more than one baby, where the risk is as high as one in two. In single pregnancies though, it’s very common for there to be no explanation as to why a baby has arrived early.
However, going into premature labour can be linked with:
- Having a very full and stretched womb (uterus). This can happen if you’re carrying twins or more, or if you have a condition such as too much amniotic fluid (polyhydramnios).
- Cervical weakness, or a short cervical length. Your sonographer will be able to pick this up at your mid – pregnancy ultrasound scan.
- A history of spontaneous premature birth.
- A bacterial infection in the bag containing the waters or in the amniotic fluid itself.
- Your waters breaking early.
- Heavy bleeding.
- Some abnormalities of the womb.
The timing of your pregnancy and other lifestyle factors have also been linked with an increased risk of premature birth. You’re at increased risk if you:
- have a short gap between pregnancies
- have a lack of emotional and financial support during your pregnancy
- smoke or take drugs, particularly cocaine
- are underweight or very overweight
- are pregnant as a result of IVF
Why might my baby need to be born early?
Your baby may need to be born early for medical reasons. If this is the case, your labour may need to be induced, or you may need an early caesarean section. About a quarter of premature births happen this way (Norman et al 2009).
Your baby needs to be born early if he:
- isn’t growing as well as he should be
- has an abnormality
Or if you have:
- a complication, such as pre-eclampsia or diabetes
- a medical condition that means it’s safer for your baby to be born early (Haas 2011, Romero et al 2014)
- suffered a trauma to your abdomen
Remember that having one or more of these factors doesn’t mean your baby will definitely be born prematurely. It just increases the chances of it happening.
What should I do if I go into premature labour?
- your waters break
- you start having contractions before you’re 37 weeks pregnant
You’ll probably be asked to go into hospital. Ask someone to drive you there, or if that isn’t possible, call the hospital and ask for an ambulance.
What will happen when baby is born?
- Extremely early (27 weeks or earlier), he will need to be cared for in a neonatal intensive care unit (NICU), which may mean he’ll be moved to another hospital. He’ll need to be kept very warm as he’ll have a high risk of hypothermia, and will need dextrose to prevent low blood sugar. He will also be at risk of low blood pressure and infection, and will need help with his breathing.
- Very early (28 weeks to 31 weeks), he is likely to be cared for in a special care baby unit (SCBU) or local neonatal unit (LNU). He will be stronger than younger babies but still at risk of hypothermia, low blood sugar and infection. He may need more specialised care at an NICU.
- Moderately early (32 weeks to 33 weeks), he may have problems with breathing, feeding and infection which require specialised care. He may be able to stay with you on a transitional care ward, or be taken straight to an LNU or SCBU.
- Early (34 weeks to 36 weeks), he may not need any treatment. He may look small but still be able to go straight to the postnatal ward with you. Or he may be admitted with you to a transitional care ward. It will depend on how well he’s feeding, and whether he has problems with blood sugar levels, blood pressure or infection.
Sadly, babies born before 22 completed weeks of gestation are unlikely to survive. Babies born at 23 weeks or 24 weeks may survive, but it depends on their birth weight and their health at birth. The further your pregnancy progresses, the better the chance your baby has.
Doctors will do their best to make sure that a baby is as comfortable as possible.
Breastfeeding is important for all babies but perhaps even more so for premature babies, who are at greater risk of infection. Breastfeeding provides additional protection against infection as well as all the nutrients a baby needs.
There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.”― Albert Einstein