Cystic Hygroma

Cystic Hygroma is an uncommon finding usually found on an early pregnancy scan.

What is a Cystic Hygroma?

This is a term used when there is a fluid filled area normally appearing on the baby's neck or head. This occurs when the lymph vessels fail to form correctly or a blockage in the baby's lymphatic system.

(The Lymphatic System is an important part of the immune system. It also helps remove extra fluid/waste from the body.)

Why has this happened?

It may be an isolated finding and can resolve and cause no problems with your baby

It can be associated with Chromosomal abnormalities –in up to half of babies found to have a Cystic Hygroma are found to have Down Syndrome or Turner Syndrome

  • There is a higher chance of miscarriage
  • Possible problems involving the heart or other organs.
  • Chance of infection such as parvovirus (slap cheek)

What happens next?

You will be seen by the Fetal Medicine Midwife (or appropriately trained midwife) to discuss the scan findings and given further information.

You will be offered further tests such as Chorionic Villus Sample or Amniocentesis (Further information regarding these procedures found on the Antenatal Screening Wales Website). These tests performed to check for chromosomal abnormalities. The first result will take approximately 3-5 working days.

A sample of your blood can be taken to check for Parvovirus. The result will be ready after 5-7 days.

If a combined test has been taken then this will give you the chance result for T21,18 and 13 only. This can take up to a week to obtain a result and you will be contacted and informed. The test is approximately 85% accurate and will not test for Turners Syndrome or any other Chromosomal disorders.

An anomaly scan will be performed at 19 weeks pregnant by a senior sonographer.

An extra scan of baby's heart will be performed at 22 weeks pregnant too.


You will be seen in Fetal Medicine Clinic at around 15/16 weeks of pregnancy (sometimes earlier) to assess the cystic hygroma has resolved and to scan baby for growth and normal development.

This leaflet may not be able to answers all your questions but when you are seen in clinic your concerns will be discussed further.


It is an understandably a difficult time for parents and please contact the Fetal Medicine Midwife on the number below if any worries.

Contact Numbers

Royal Gwent Hospital 01633 234747

Nevill Hall Hospital 01873 732390 or 01873 732391

Useful Websites

ARC (Antenatal Results and Choices) - Offer information and support to parents who are making decisions before, during and after tests in pregnancy

Tel no: 084507722990


Email: info@arc-uk-org

ASW (Antenatal Screening Wales)


Improving the physical and emotional health and wellbeing of expectant mothers, infants, children and young people throughout Aneurin Bevan University Health Board Area.

(N.B: The Family and Therapies team at ABUHB is NOT responsible for the content on the webpage links that we refer to in our resource sections and linked information to external sites. All information was accurate and appropriate at the time the webpage was created.)

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