Your baby is surrounded by amniotic fluid inside the amniotic sac and this fluid protects your baby and helps him to grow and develop properly.
The amount of fluid which surrounds your baby can vary on a day to day basis as your baby swallows fluid and passes urine into it daily.
The amount of amniotic fluid around your growing baby increases as your pregnancy progresses. On average, in a normal pregnancy by 36 weeks pregnant, you will have between 800ml and 1000ml of amniotic fluid surrounding your baby. This amount normally begins to decrease from 37 weeks onwards in preparation for labour.
In a very small percentage of pregnancies it is possible for there to be too much amniotic fluid (polyhydamnios) or too little fluid (oligohydramnios) surrounding your baby.
Does low amniotic fluid affect my baby?
The effects of low amniotic fluid does depend on what stage of pregnancy you are, and the level of fluid surrounding your baby.
Unfortunately, if low levels of amniotic fluid are found in the first trimester, there is a very high chance of miscarriage. If low levels are detected in the third trimester, usually nothing is required apart from extra scans and check-ups to ensure baby is well.
As you approach labour, your baby may be unable to move into position for child birth due to the lack of amniotic fluid and may end up in a breech position (bottom down) instead of the preferred head-down position. This usually means that your baby will not to be born by caesarean section.
During labour, there is a higher chance that your baby may become distressed due to the low levels of amniotic fluid. You and your baby will need to be closely monitored during labour and your baby may need to have help to stabilise his breathing after birth. It is also possible that your baby’s umbilical cord can get squashed during labour by your baby because there is less fluid for your baby to move. Your baby will be fully monitored and if he becomes distressed, you may need to have a caesarean section.
What are the causes for low amniotic fluid?
There are some cases when the cause for low amniotic fluid is unknown, however the main causes of low amniotic fluid include:
- Your waters have broken – Your waters can break with either a gush of fluid or a gentle leak over time. It is common for women to confuse their waters breaking with passing or leaking urine. If you think your waters may have broken, you should contact your midwife who will advise you in your situation. If your waters break, but you do not go into labour; you may need antibiotics to protect you and your baby from infection as your baby will no longer be protected. It does depend on the stage of your pregnancy but you may need to have your labour artificially started.
- A problem with the placenta – Low amniotic fluid can be caused if you have a condition such as lupus, high blood pressure, pre-eclampsia or diabetes which prevents the placenta from working properly and stops it from supplying the correct amount of blood and nutrients to your baby. You will need to be closely monitored throughout your pregnancy and you will need extra scans in order to track the amniotic fluid levels.
- Dehydration – You should ensure that you drink plenty during pregnancy and ensure that you eat healthily as being dehydrated may cause low amniotic fluid.
- Medicines – Unfortunately, some medicines which you may be taking can cause low amniotic fluid. These types of medicines are not usually prescribed to pregnant women but include ibuprofen, anti-inflammatories and some treatments for high blood pressure. If you are concerned about any medicines you are taking, speak to your doctor for advice.
- A health problem – It is possible that low amniotic fluid is caused by your baby not passing enough urine which may mean that he has a problem with his kidneys or that he has a chromosomal abnormality. This would normally be detected during your 20 week scan. If this happens, you will be referred to a specialist and be monitored and looked after throughout your pregnancy.
- Being overdue – As the levels of amniotic fluid begin to decrease from 37 weeks, it is possible that you will be classed as having low levels of amniotic fluid if you go beyond your expected due date.
Can I prevent it? What should I do?
Unfortunately there is not really anything you can do to help your amniotic fluid levels. However, you should try and remain as calm as possible throughout your pregnancy. You should rest as much as you can and try and sleep well. You should keep yourself hydrated by drinking plenty of water and you should ensure that you are eating a healthy and mixed diet.
You should listen to the advice given to you by your doctors and midwives and ensure you attend all appointments and check-ups.
If you have any concerns about your amniotic fluid levels, you should speak to your midwife or doctor.
by Jenny, mum to William and James
