Congenital Diaphragmatic Hernia

Introduction

Congenital diaphragmatic hernia (CDH) is a condition in which the abdominal contents protrude into the thoracic cavity through a diaphragmatic defect. This interferes with normal lung development.

Infants with congenital diaphragmatic hernia requiring surgical assessment and/or intervention are transferred from regional hospitals to the Hong Kong Children’s Hospital (HKCH) for further management.

Causes and Risk Factors

The overall prevalence of CDH is 2.3 in 10,000 births. The main risk factors identified for CDH are male sex and advanced maternal age. Around 10-15% of CDH cases are caused by chromosomal anomalies or monogenic disorders. In most cases, there is no identifiable genetic cause.

Signs and Symptoms

Around two-thirds of patients are diagnosed antenatally, while one-third are diagnosed postnatally with symptoms and signs including breathing difficulty, cyanosis (inadequate oxygenation in blood), deviated heart apex position and abdomen that appears caved in. Some cases are asymptomatic and are diagnosed following an incidental finding on X-ray. In severe cases, babies may develop respiratory and circulatory failure requiring mechanical ventilation and other cardiorespiratory support.

Diagnosis

Most cases of CDH are diagnosed antenatally on ultrasound. The remaining cases are diagnosed after birth, either in early or late infancy after the above signs and symptoms are picked up. A simple chest X-ray (showing bowel loops herniated into the thoracic cavity) usually confirms the diagnosis. Sometimes a computed tomography scan may be required to differentiate CDH with a small defect from diaphragmatic eventration.

Treatment and Management

NICU Care

Depending on your baby’s condition soon after birth, the clinical team of the birthing hospital will choose the ventilation strategy that is most suitable for stabilizing the lungs and heart. High frequency oscillatory ventilation may sometimes be used and may be continued when your baby arrives at HKCH. Initial stabilisation before surgery may take days to weeks.

Each baby will be carefully handled in the NICU by our experienced nursing team and neonatologists to ensure every body system is optimized before surgical repair. Some babies who are on the severe end of the disease spectrum with severe pulmonary hypoplasia and pulmonary hypertension (with or without heart failure) may require extracorporeal membrane oxygenation (ECMO) support.

Surgical Repair

Your baby will receive general anaesthesia and will be monitored by our paediatric anaesthetists during surgical repair. The type of repair procedure depends on how big the defect is. Our paediatric surgeons will explain the whole procedure to you and make sure you understand it before proceeding.

Recovery

After surgery, your baby will begin to recover. The first process is to wean off the ventilator. Feeding will be introduced via a gastric tube when the gut is ready. Oral feeding will be introduced when your baby’s breathing tube has been removed, and is receiving oxygen flow support at two litres per minute or below. The duration of ventilator weaning and the total length of hospital stay largely depend on the severity of the disease and its response to treatment. In the NICU, most babies with mild to moderate CDH would need to stay for up to one to two months before getting home. For severe cases, their hospital stay can be up to three months or longer.

Discharge and Follow-up

Your baby can be discharged from our unit when he or she is breathing, feeding and growing well. Our hospital offers multidisciplinary follow-up for babies with CDH. Our medical and surgical teams will monitor your little one’s heart, lungs and gut condition after surgical repair, and our occupational therapists will offer developmental screening. In case of specific organ involvement (e.g. brain, heart), your child will also be referred to the relevant subspecialty team for follow-up. Pulmonary function test will be arranged when your child is older. Subsequent follow-up arrangements will depend on each individual’s progress.

References

• SL Lee, MS Wong. Congenital Diaphragmatic Hernia: a Hong Kong experience on the respiratory status and outcome. HKJPaediatr (new series) 2023;28:203-208
• RMS Wong, AHY Lee. Congenital Diaphragmatic Hernia, Survival outcomes over the years. HKJPaediatr (new series) 2023;28:203-208

Acknowledgement

Principal author: Dr Lee Hoi-ying on behalf of Neonatal Team, HKCH

Initial posting: Oct 2026

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