Pre-labour rupture of membranes at term
In this article:
- What happens when your waters break early?
- What is pre-labour rupture of membranes?
- How will I know if my waters have broken?
- When will my labour start?
- Can a ruptured membrane heal itself?
- What is prolonged rupture of membranes?
- Signs of infection
- Induction of labour for PROM
- PROM and labour
- Main points
What happens when your waters break early?
Waters will break before labour starts in up to 10% of women who are at term (more than 37 weeks). In this article we discuss what happens in this situation.
What is pre-labour rupture of membranes?
“Membranes” are the layers of thin tissue that enclose your baby and amniotic fluid (“waters” or “liquor”) inside your womb. It is also known as the amniotic sac or pregnancy sac. Once the membranes have “ruptured” or broken, the amniotic fluid around your baby leaks out. This is a normal process of labour.
Pre-labour rupture of membranes (PROM) at term is when your waters have broken after 37+ weeks of pregnancy and labour has not yet started or become established — i.e. you are not having regular and painful contractions that are causing your cervix to dilate. This occurs in 8-10% of pregnancies. When this happens, it is advisable for you to inform your midwife or local maternity unit. They may wish to do a speculum examination, in which they look at the neck of the womb or “cervix” to confirm that your waters have broken as well as to check the general wellbeing of you and your baby. They will also use this as an opportunity to talk through your management options.
How will I know if my waters have broken?
When your waters break, it may be really obvious, for example, you may experience a large gush of fluid and feel like you’ve wet yourself or it may experience a slow trickle of fluid. The type of leak depends on the size of the hole, the positioning of your baby and whether the hole is directly in front of the baby’s head (“forewater leak”) or above the baby’s head (“hindwater leak”). It’s always advisable to get checked if you are unsure.
When will my labour start?
There is an increased chance that labour will start when your waters break. You may experience contractions, or tightenings (mild irregular contractions) and you may pass a mucus plug or “show”. Of women at term who have PROM, about 60% will go into labour on their own within 24 hours and 90% within 48 hours.
You should contact your midwife once your waters break and you will need to attend your local unit for assessment. It is likely that you will then be sent home to await labour.
While you wait for labour to start, there are a few things that you can do to keep you and your baby safe:
- Keep active and upright as much as possible. This will help your baby to descend into the pelvis and put pressure on the neck of the womb (cervix) to encourage labour to start. If you do feel like lying down, do not lie flat on your back; prop yourself up with pillows, or lie on your side.
- Involve your birth companion(s). They can support you through this time to ensure that you feel as comfortable as possible. They can also provide encouragement and practical help.
- Continue to eat and drink normally. This will keep your energy levels up.
- Monitor fluid loss. It is important that you keep an eye on the colour and consistency of the fluid. Any amniotic fluid leaking out should be clear and water-like, although can have bits of “show” in it. “Show” can look jelly-like with streaks of blood in it and is usually passed when labour starts. Normal amniotic fluid does not have a strong smell. If you notice any significant change in the colour, consistency or smell of the fluid, then you should call your maternity unit/hospital. Change your sanitary pad every four hours; it may be worth keeping your pads as your midwife or doctor may wish to see them.
- Monitor your temperature every four hours when you are awake. If it is over 37.5 degrees or you feel unwell or hot and sweaty, you should call your maternity unit/hospital as it may be a sign of infection.
- Have a warm shower.
- Monitor baby’s movements.
- Avoid sexual intercourse once waters are broken as this may increase the risk of infection.
Can a ruptured membrane heal itself?
In some circumstances, the ruptured membranes may reseal themselves. This is more likely to occur if the break in the membranes is very small and if there is no infection present. In women who have premature rupture of membranes (rupture of membranes before 37 weeks) it might be worth waiting to see if this happens. However, if the membranes have ruptured at term you should be expecting to meet your baby within the next few days.
What is prolonged rupture of membranes?
Prolonged rupture of membranes is when the waters have been broken for more than 24 hours and labour has not started on its own.
At 24 hours you will usually be offered an induction of labour to expedite the arrival of your baby.
Prolonged rupture of membranes at term increases the risk of neonatal infection from 0.5% to 1%. This is because the amniotic sac acts as a protective seal against infection during pregnancy. Once there is a hole in it, there is a chance that infection can enter the womb (chorioamnionitis). Theoretically this risk is there immediately, but it gets higher with every hour that passes before your baby is born. As the majority of women will go into labour before 24 hours, it is reasonable to wait 24 hours before recommending induction to expedite delivery and hence reduce the risk of infection. Every unit will have their own policy based on their own populations of women and observed infection rates. Induction might be offered earlier (12-18 hours after your waters break) or later depending on where you deliver your baby. Ideally, babies should be born within 96 hours of waters breaking.
Signs of infection
It is important for you to phone the hospital if:
- You feel unwell
- You are shivering
- Your temperature is above 37.5’C
- The amniotic fluid is foul-smelling
In the 24 hours that you are waiting, monitor your temperature every 4-6 hours or if you feel unwell.
Induction of labour for PROM
If your waters have been broken for more than 24 hours and labour does not start on its own accord, you will likely be offered induction of labour. A doctor will discuss the different methods of induction and the risks and benefits of each. Usually these will involve:
- A prostaglandin gel/tablet inserted into the vagina to help the cervix prepare for labour.
- An intravenous oxytocin hormone infusion.
If you do not wish to be induced, you may be offered “expectant management”, which generally involves waiting to see whether labour starts on its own accord but with close monitoring. This includes regular temperature recordings, monitoring of baby’s movements and heart rate, monitoring the amniotic fluid colour and smell, and reporting of other symptoms. You may be admitted as an inpatient for this process. The lengthy of time you should wait for labour to start naturally is a conversation for you and your doctor in which you will weigh up the benefits of a natural labour against the risk of infection.
PROM and labour
If your waters have been broken for more than 24 hours you will need extra monitoring during labour, whether your labour has begun naturally or you are having an induction. You will be closely monitored for signs of infection (an increased temperature and heart rate) in you and your baby.
After delivery, it is recommended that you stay in hospital for at least 24 hours so you and your baby can be closely monitored. If there are any signs of infection, you and your baby will have an infection screen and may need to be started on antibiotics.
- The amniotic sac or membranes are a seal around the baby and the amniotic fluid. The membranes help development in the womb and protect against infection.
- The waters normally break during labour for the majority of women, but in up to 10% of women may break before labour starts.
- If your waters break before labour, there is a 60% chance that your labour will start in the next 24 hours.
- Prolonged rupture of membranes is when labour has not started within 24 hours of the membranes breaking.
- Induction of labour will be offered at 24 hours to reduce the risk of infection.
- You should contact the hospital if you have any signs of infection (feeling unwell, shivering, fevers or temperature greater than 37.5’C or foul-smelling amniotic fluid).
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Important – If you or your child are unwell you should seek medical advice from a professional – contact your GP or visit an A&E department in an emergency. While My BabyManual strives to provide dependable and trusted information on pregnancy and childcare 24/7 via our website pages, we cannot provide individual answers to specific healthcare questions.