Congenital diaphragmatic hernia (CDH)


What is CDH?

It is a condition where the baby’s diaphragm has not formed correctly leaving a defect (hole). The diaphragm is a thin sheet of muscle which keeps the chest and stomach separate and helps us to breathe.

Due to the defect (hole), organs such as stomach, bowels and liver can be taken up where the lungs and heart should be, this can prevent the lungs from growing normally.

Why does this happen?

It is unclear why this happens. It is not caused by something you have or have not done. Rarely it can be associated with an underlying genetic condition.

What happens next?

You will be able to discuss the scan findings with the Fetal Medicine midwife or appropriately trained professional. You will be referred to the Fetal Medicine Clinic and will be given an appointment to see the Consultant Obstetrician for further discussion and another scan to confirm the diagnosis.

How does CDH affect the baby?

Unfortunately, this is a serious condition. Many babies with CDH have problems with their lungs called Pulmonary Hypoplasia. This is due to the lungs being smaller and squashed.

Another issue may be increased pressure in the arteries in the lungs (pulmonary Hypertension).

There is an association with heart defects.

Normally CDH is isolated but about one in ten babies may have a chromosomal or genetic disorder

The outlook is guarded and prognosis for survival remains around 50 per cent although can be higher in certain centres.

Picture of CDH



Understandably this is an incredibly stressful and difficult time for you. If you have any further questions, please contact the Fetal Medicine Midwife on the contact numbers below.

Contact Numbers

Royal Gwent Hospital 01633 234747

Nevill Hall Hospital 01873 732390 or 01873 732391

Bristol Fetal Medicine Unit 0117 3425470 website: University Hospital Bristol Fetal Medicine unit 

Cardiff Fetal Medicine Unit 02920 742279

Bristol Cardiology Unit 0117 3425394

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)




Tel no: 08007316991


CDH support group on Facebook.

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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