Polyhydramnios is where there is too much amniotic fluid around the baby during pregnancy. Amniotic fluid is the fluid that surrounds your baby in the womb.

Too much amniotic fluid is normally spotted during a check-up in the later stages of pregnancy.

It isn't usually a sign of anything serious, but you'll probably have some extra check-ups and will be advised to give birth in hospital.

Will I have a healthy pregnancy and baby?

Most women with polyhydramnios won't have any significant problems during their pregnancy and will have a healthy baby.

But there is a slightly increased risk of:

  • pregnancy and birth complications, such as giving birth prematurely (before 37 weeks), problems with the baby's position, or a problem with the position of the umbilical cord (prolapsed umbilical cord)
  • your waters breaking early
  • heavy bleeding after your baby is born because your womb has stretched
  • a problem with your baby

You'll need extra check-ups to look for these problems, and you'll normally be advised to give birth in hospital.

Symptoms of polyhydramnios

Polyhydramnios tends to develop gradually and there may not be noticeable symptoms.

Some women experience:

  • breathlessness
  • swollen feet
  • heartburn
  • constipation
  • feeling your bump is very big and heavy

But these are common problems for pregnant women and aren't necessarily caused by polyhydramnios. Talk to your midwife if you have these symptoms and you're worried.

In rare cases, fluid can build up around the baby quickly. Contact your midwife or doctor if your tummy gets bigger suddenly.

Tests, checks and treatments if you have polyhydramnios

During the rest of your pregnancy, you'll probably have:

  • extra antenatal appointments and ultrasound scans to check for problems with you and your baby
  • tests to look for causes of polyhydramnios, such as a blood test for diabetes in pregnancy or amniocentesis (where some amniotic fluid is removed and tested)
  • treatment for the underlying cause, if one is found – for example, changes to your diet or possibly medication if you have diabetes

Sometimes you may need treatment to reduce the amount of fluid. Some may be drained with a needle or you may be given medication to help stop more fluid being produced.

Your midwife or doctor may also talk to you about any changes to your birth plan.

Things you can do if you have polyhydramnios

If you've been told you have polyhydramnios:

  • try not to worry – remember polyhydramnios isn't usually a sign of something serious
  • get plenty of rest – if you work, you might consider starting your maternity leave early
  • speak to your doctor or midwife about your birth plan – including what to do if your waters break or labour starts earlier than expected
  • talk to your midwife or doctor if you have any concerns about yourself or your baby, get any new symptoms, feel very uncomfortable, or your tummy gets bigger suddenly

You may find it useful to speak to other women who've had polyhydramnios. You could try joining an online forum such as the NCT HealthUnlocked forum.

Labour and giving birth if you have polyhydramnios

You'll normally be advised to give birth in hospital. This is so any equipment or treatment needed for you or your baby is easily available.

You can usually wait for labour to start naturally. Sometimes induction (starting labour with medication) or a caesarean section (an operation to deliver your baby) may be needed if there's a risk to you or your baby.

You'll probably pass a lot of fluid when you give birth – this is normal and nothing to worry about. Your baby's heartbeat may also need to be monitored during labour.

After giving birth, your baby will have an examination to check they're healthy and they may have some tests – for example, a tube may be passed down their throat to check for a problem with their gut.

Causes of polyhydramnios

It's often unclear why too much fluid sometimes builds up during pregnancy, but it can be caused by:

  • a twin or multiple pregnancy
  • diabetes in the mother – including diabetes caused by pregnancy (gestational diabetes)
  • a blockage in the baby's gut (gut atresia)
  • a problem with the placenta
  • the baby's blood cells being attacked by the mother's blood cells (rhesus disease)
  • a build-up of fluid in the baby (hydrops fetalis)
  • a genetic problem in the baby

Most babies whose mothers have polyhydramnios will be healthy. Speak to your doctor or midwife if you're concerned or have any questions.

The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website nhs.uk
Last Updated: 13/07/2021 13:48:56