Care for premature babies has developed over the years and the outcome for pre-term or premature babies has greatly improved. However, being born prematurely can still have serious effects on babies and their long term health. Further research is needed, as many of the causes are still unknown. Find out more about pre-term birth, access the expert interview, read another woman’s story, find out the truth behind common myths and see the research we are funding.
In the UK 1 in 13 births are premature
The definition of a 'premature' or 'preterm' baby is one that is born before 37 and after 24 full weeks after the first day of the mother's last period. A baby born at 37 weeks or more is known as a 'term' baby. There are different levels of prematurity and these carry their own risks. Generally the earlier the baby is born the higher the risk of health problems.
We still have a lot of learn about premature birth so it's not always possible to explain why it happens. In about 40 percent of cases, the woman's labour is triggered by an 'unknown cause'.
Premature birth rarely happens because of one single thing - often it is caused by a combination of different complex factors.
Many mothers of premature babies suffer from feelings of terrible guilt - wondering what they did wrong and if they are to blame. The truth is that in the vast majority of cases there is nothing that could have done to prevent premature birth.
The main risk factor for premature delivery is a previous premature delivery. The more premature deliveries, and the earlier the babies were born, the higher the risk of premature delivery in a future pregnancy.
Risk factors include
· Being pregnant with the first baby
· bleeding in a previous pregnancy
· having had one or more abortions
· a history of cervical trauma, such as treatment for an abnormal smear test
· a previous abdominal injury (for example, because of physical violence or if in a car crash).
Infections can trigger premature birth. Research suggests that infections are at least partly to blame for one third of premature births, particularly for women who go into labour before 30 weeks.
· Intrauterine infections (infections within the womb) - these are caused by bacteria, and may be responsible for up to 40 percent of premature births.
· Genital tract infections - includes bacterial vaginosis, chlamydia, trichomona, gonorrhoea, syphilis and HIV (but not thrush) and have been associated with waters breaking early and premature labour.
· Urinary tract infections (UTIs) - UTIs affect about five percent of pregnant women. In between one third and a half of those women, the UTI will travel up into the kidneys, causing acute pyelonephritis, a kidney infection that can cause premature labour
· Chorioamnionitis - this is an infection of the membranes of the sac that holds the baby and the fluid in the womb. If the waters break early (also known as preterm premature rupture of the membranes, or PPROM for short) the fluid is more susceptible to infection, as the sac is no longer sealed. Chorioamnionitis may trigger premature labour.
Symptoms of chorioamnionitis:
· high temperature
· foul-smelling vaginal discharge
· fast heart rate in mother or baby
· abdominal pain
Other causes include:
· Gestational diabetes -diabetes that develops during pregnancy. It affects around 14 in every 100 pregnant women. It is associated with premature labour and needs careful monitoring.
· Waters breaking early (PPROM) - the membranes that make up the sac holding the baby usually break at the start of labour. If the waters break before full term, the medical name for it is preterm premature rupture of the membranes, or PPROM. If this happens early, before the contractions start, it can (but does not always) trigger early labour.
If you suspect your waters have broken early phone the hospital for advice immediately.
Assessment of premature labour risk
Some babies simply arrive early without warning, but if known to be at risk of premature birth, the healthcare team will prepare for it and treatment may include delaying the birth if possible to give the baby more time to develop.
However, with certain types of infection or severe pre-eclampsia, or if your baby has a health problem, then the team may actually advise to have the baby early, by induction or caesarean, if this is the safest option overall.
Certain test results or events will show the team immediately if there is a higher risk of premature delivery, for example the mother having very low weight for height.
If at risk of having a premature baby further tests may include
· blood tests
· urine samples
· vaginal swabs
· ultrasounds scans.
Ultrasound scans can reveal a range of factors that have been linked to premature delivery. These include:
· the length of the cervix
· size of the womb
· size and position of the baby
· whether carrying more than one baby
· size and position of the placenta
· amount of amniotic fluid.
If the results reveal a potential problem, the healthcare team can take action as quickly as possible.
If at risk of having your baby early, you will have regular monitoring and contact with the healthcare team - often including a specialist. As far as possible, the medical team will aim to delay the birth to enable the baby to develop as much as possible.
Reducing the risks of premature birth
· Maintain a healthy weight - being overweight or underweight will make it more likely to develop complications that could contribute to a premature birth.
· Remain physically active - boosts overall wellbeing and reduces your risk of conditions such as diabetes and pre-eclampsia, which can lead to premature birth.
Note: If you have been diagnosed with any of the conditions associated with premature birth, please consult with your healthcare team before starting a new exercise plan or embarking on activity:
· Stop smoking – smoking is clearly linked with premature labour
· Follow alcohol consumption guidelines
· Get treatment for sexually transmitted infections (STIs).
· Avoid animal-borne infections
· Prevent food poisoning
· Look after your teeth and gums - scientists have found a link between tooth decay, gum disease and premature birth, suggesting that inflammation and infection in the gum may be associated with premature labour. The experts agree that this probably does not directly cause premature labour, but it's another good reason to practise good oral hygiene.
Delaying a premature birth
The healthcare team will try to prevent the birth of the baby if possible and if it does not endanger the baby or mother.
If over 35 weeks of pregnancy or if the baby or mother are in danger, the healthcare team will most likely allow the birth to go ahead, or induce the birth. If under 35 weeks, treatment to slow down labour or delay the birth may be required in order to allow time to:
· administer corticosteroids to help the premature baby's lungs develop
· transfer the woman to a medical unit that can offer the right level of care
Babies born prematurely are more likely to have health problems. To help reduce the risks, medication may be required during or after labour.
To delay, stop or slow down the labour. Tocolytic drugs slow down contractions. Usually they delay the birth by a couple of days, giving the team time to transfer the woman to a hospital with the appropriate facilities and to give you corticosteroids or antibiotics to help the baby stay as healthy as possible.
Corticosteroids help the baby's lungs and brains develop more quickly. They are injected into the woman’s arm or leg, and work within about 24 hours.
Once given corticosteroids the baby will be far less likely to develop respiratory distress syndrome and some other complications.
If a woman is considered at risk of having her baby prematurely, she may be offered corticosteroids from about 23 weeks. If the tocolytics succeed in delaying your labour, another dose of corticosteroids at a later stage may still be given - if still at risk.
Premature babies are particularly susceptible to infection. If the membranes have ruptured prematurely, antibiotics may be required to protect from infection.
If there is a risk to the baby's or mother’s health, labour can be induced (started artificially) e.g. in pre-eclampsia or fetal growth restriction.
Transfer to a neonatal unit
Moving to a specialist neonatal unit may be the safest option if the baby is likely to be born very prematurely.
For some women, it's safer not to move. In infection or severe pre-eclampsia, or if there are problems with the baby or with the placenta, then the team will need to deliver as quickly as possible.
Treatment options for premature babies:
Treatment depends of the health of the baby and how early it is born. Babies born between 34-36 weeks normally need help with maintaining temperature and feeding. In many cases this may not require care on a neonatal intensive care unit and these babies can be looked after on a specialist ward. Babies born earlier than 34 weeks will almost certainly need help with breathing and will require care on an intensive care unit.
Treatment can include:
Care in an incubator or warm cot to help maintain temperature.
Breathing support by either a ventilator or continuous positive airway pressure system
Administration of surfactant to help with breathing.
Drips to provide food, fluid and medicines.
Help with feeding.
Blood tests or transfusions.
Scans, surgery or other medical interventions.
It can be very daunting for parents whose baby is born early, especially if intensive treatment is required. A long stay in neonatal intensive care unit may be needed and complications can develop over time. However, staff are highly skilled and trained to help parents in this situation. Asking questions, being as involved as possible with baby care and making contact with other parents in a similar situation is encouraged and may help.
Do not be afraid to ask for help and support, from friends, midwives, doctors and family.
Pre-term Birth: Text Version.
Hello and welcome to our podcast.
Today we will be speaking about pre-term birth with Professor Donald Peebles who is Head of the Research Department of Obstetrics at UCL (University College London) and a consultant obstetrician.
More research is needed into pre-term birth. 1 in 13 babies are born prematurely in the UK and premature birth is responsible for most neonatal deaths and long term problems. Survival rates have greatly improved but the number of babies being born prematurely has not decreased.
Hello Donald thanks for joining us. One your specialist research areas is premature labour and it’s great to have your expert opinion on this.
Could you first help us to understand what is pre-term birth?
Most women have their babies after 37 weeks of pregnancy and pre-term birth is when you have a baby before that. The time that we are really worried about is when women have their babies very prematurely which could be more than 3 months before 40 completed weeks of pregnancy.
Could you tell us a little bit more about what are the short and long term effects it can have on babies?
So, pre-term birth is a problem much more for the baby than it is for the mum and the reason that we are so concerned about babies who deliver very early is that they are more likely to die immediately after birth. That is because by and large their organ systems haven’t had time to develop properly and they are not fully mature. So for instance their lungs aren’t fully adapted for breathing air until about 35 or 36 weeks of pregnancy. Babies born 3 months early may need to have help with breathing, supplementary oxygen, ventilation and can go on and have long term complications with their lungs like asthma or respiratory difficulties. The other main organs that have not developed and can cause problems are the brain. Babies born prematurely are more likely to have long-term problems with brain development like a slightly lower IQ and also the intestines aren’t fully developed for coping with things like maternal breast milk; so one has to very carefully introduce feeding by mouth in these very premature babies.
We don't always know why women go into labour early. Could you explain a little bit more about the causes and risk factors for premature labour?
It remains something of a mystery and that is why we are so keen on doing research. Why what is a normal process at 40 weeks of pregnancy (women going into labour) should occur out of the blue in some women as early as 23 or 24 weeks of pregnancy. We do know that there are some things that make you more at risk of having a baby prematurely; if you have had a preterm baby before then that would increase the risk slightly of it happening again, we know that if you have multiple pregnancies like twins or triplets that can increase the risk of having a baby prematurely and we also know that people who have had surgery on the neck of the womb (the cervix) are slightly more at risk of having pre-term births. So we know that there are some associations but still the majority of pre-term births occur in women with very few risk factors.
Are there any symptoms or warning signs that women should be aware of/ watch out for?
The most common presentation is people actually feeling or experiencing the symptoms of labour; so they are the same symptoms that you would experience when you went into labour normally at 40 weeks but you experience them at say 24 weeks of pregnancy. So that would be things like rupturing the membranes- water coming out vaginally, having painful contractions which are quite regular or sometimes of bleeding. Occasionally, particularly if the cervix doesn’t work very well, there can be very few symptoms. The cervix can open up really quite quietly without causing much in the way of discomfort and women notice increase in vaginal discharge, a feeling of discomfort and they might choose to go in and be checked over, and at that stage it could be seen that the cervix has actually opened up quite substantially.
Can you take us through the types of treatment that women might expect to have discussed with them? So as you were saying before, it does depend on the circumstances if membranes have ruptured or if they haven’t….
At the moment the risk of pre-term birth will only become apparent when people actually present with early signs of preterm labour. Now the encouraging thing is that even if you have contractions quite frequently, the majority of women who present like that actually aren’t in pre-term labour and if you do nothing the contractions will just settle down and go away; but what we try and do as midwives and doctors is to focus our treatments and care on those who are actually going to go into pre-term labour. The management at the moment would be to try and temporarily stop the contractions using drugs which relax the muscles of the womb. That only postpones the pre-term birth, but that is important because it means that we can give the mother two injections of steroids which cross the placenta and they mature the baby’s lungs and brain and so improve some of those complications that I talked about earlier. The other thing that we can do is we can use that 24 or 48 hours to ensure that the mum actually delivers the baby in a hospital which has specialist facilities for optimizing the care of these very pre-term babies.
I understand you are supervising one of the studies Wellbeing of Women are funding about the role of the immune system of the cervix in preventing pre-term birth. Can you tell us a little bit more about that?
One of the things that we really need to do with research is to identify women who might have a pre-term baby, before they actually go into pre-term birth. This is because by the time they go into pre-term birth the number of treatment options are very limited and it is very difficult to prevent. So we are interested in looking at factors that you might be able to study early in pregnancy which mean women are at an increased risk and one of the things that we are focusing on is the cervix (the neck of the womb). The reason that we are interested in the cervix is because we know that in all women the vagina, like the mouth, is full of bacteria and we know that in most women by the time they get to the end of pregnancy, the inside of the womb is a sterile cavity so there are no bacteria. But what we also know is that women who have pre-term babies, by the time they go into pre-term labour often the womb has bacteria inside it. So we think that one of the reasons that might happen is that the cervix which acts as a barrier between the vagina in the inside of the womb perhaps doesn’t function properly to keep bacteria out. We can study the cervix early in pregnancy both by using ultrasound to measure how long it is and therefore how effective a barrier it is and we can also take swabs from the cervix to look at proteins which are made by the cells lining the cervix, which might kill bacteria and stop them getting into the womb. Our speculation is that women who have poor cervical function for whatever reason might be at an increased risk of pre-term birth. If that were the case then we are also looking at ways of intervening to improve the function of the cervix to try and reduce the risk of prematurity.
So if that was proven possibly, you would be able to identify women at risk and look at treatments…
Yes, as I said if somebody comes in, in pre-term labour that is probably the end result of a very long sequence of events involving hormones and proteins in the uterus which put somebody into labour. To prevent that from happening you have to get in at the beginning of that sequence of events and so we think that early treatment and prevention is the only way of doing that and that might be as early as 12 weeks of pregnancy. The idea would be that at 12 weeks we look at the cervix and assess its function and then we say somebody is at risk. Is there a treatment that we can give them then to prevent pre-term labour?
So preventative and looking at from really early on the cause…
Is there anything women can do themselves to reduce their risk?
There aren’t any specific interventions that have been found to improve the risk of preterm birth. There is no doubt that all pregnancy complications are reduced in people who go into pregnancy in a healthy state. So for instance there is an association between bad tooth care and pre-term labour. As part of preparation for pregnancy, having a very good diet, stopping smoking or drinking much and having your teeth put in good order, they are all very good things.
And also making sure if you have any concerns or worries that you voice these and get these things checked out early, rather than leaving something that you are concerned about…
That’s absolutely true. For most women the risk of pre-term labour would be very small but certainly for women who have had a previous pre-term baby then pregnancy represents an extremely anxious making time.
Apart from the research that you are currently involved in, is there any other area of this topic that you feel there is a great need for further research?
One of the difficulties with research in this area is that it’s important to be clear what is the most important outcome from the research. For pregnancy doctors (obstetricans) the most important outcome in the past has thought to be when the mother actually delivers. So all treatments have been designed to make delivery later and the assumption has been that that leads to an improvement in the outcome of the baby. More recently it has become clear that the outcome that really matters for women is how their baby does. So it’s the long term outcome of the baby which is really the important thing and it’s become clear that just delaying an inevitable delivery doesn’t necessarily improve the outcome of the baby. I think one of the most important things for future research is to follow babies up after pre-term birth or after any treatment to prevent it, to make sure that in 5 or 10 tears time those babies actually do better as a result.
Is there anything else that you would like to add to the subject that we haven’t discussed?
There are other exciting areas of research that have been carried out in this country. There is a ramdomised control trial currently ongoing, looking at progesterone which is a hormone that is naturally made which is thought to be responsible for keeping the baby in the womb until the right time. So the trial is looking at that whether giving women progesterone can actually prevent pre-term birth. That’s another exciting area of research.
Thanks very much for joining us today it’s great to have your expert opinion.
It’s a pleasure.
Find out the answers to common myths surrounding pre-term birth.
It is my fault that my baby has been born early
Pre-term labour is extremely unlikely to be your fault. There may be a variety of factors beyond your control which may have contributed such as, infection, illness, or an existing problem. If you ever experience these feelings is it important to talk about it and work through it. Speak to your doctor, midwife, neonatal nurse or support worker who will be able to offer support and further assistance if needed.
There is nothing I can do to prevent it
Often women go into pre-term labour without any risk factors. However, there are certain things that can be done to reduce the risk. Attend all routine appointments, report any symptoms or problems early on, maintain a healthy diet and lifestyle and avoid smoking, using drugs or drinking alcohol.
Spicy foods cause you to go into labour early
This is not true. Food poisoning and infection can cause premature labour but spicy food alone does not.
Having sex causes premature labour
Sex alone does not cause preterm labour. However, if you have a known risk of preterm labour or any other problems then doctors may advise avoiding sex during the pregnancy.
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Page last updated February 2013