Congenital diaphragmatic hernia (CDH) is a life-threatening birth defect affecting approximately 1 in 2,500 to 1 in 3,500 live births, with an estimated 1,600 cases diagnosed annually in the United States. It occurs when the fetal diaphragm fails to close completely during weeks 8–10 of gestation, allowing abdominal organs—including the stomach, intestines, spleen, and sometimes the liver—to migrate into the thoracic cavity. This displacement compresses developing lungs, leading to pulmonary hypoplasia and persistent pulmonary hypertension of the newborn (PPHN). Mortality remains significant at 20–30% in high-volume centers like Children’s Hospital Los Angeles and Cincinnati Children’s Hospital Medical Center, though survival has improved markedly since the 1990s due to advances in prenatal diagnosis, neonatal intensive care, and standardized protocols such as the CDH Study Group Registry (established in 1995, now encompassing over 12,000 infants across 80+ centers).
What Is Congenital Diaphragmatic Hernia?
CDH is a structural anomaly defined by a defect in the posterolateral (Bochdalek) or anterior (Morgagni) portion of the diaphragm. Over 90% of cases are Bochdalek-type, occurring on the left side in roughly 85% of infants—most commonly through the pleuroperitoneal canal. The defect size varies widely: small (<1 cm) defects may cause minimal respiratory compromise, while large defects (>3 cm) often involve herniation of the left lobe of the liver, stomach, and multiple loops of bowel into the left hemithorax. This results not only in mechanical compression but also in impaired alveolar and vascular development. Lung-to-head ratio (LHR), measured via fetal MRI or ultrasound between 22–26 weeks’ gestation, is a validated prognostic tool: an LHR <1.0 correlates with 75% mortality, whereas LHR ≥1.4 predicts >85% survival in non-ECMO candidates.
Unlike acquired diaphragmatic injuries from trauma, CDH is present at birth and arises from disrupted mesenchymal migration and fusion during embryogenesis. The diaphragm forms from four embryonic components—the septum transversum, pleuroperitoneal folds, dorsal mesentery of the esophagus, and muscular ingrowth from body wall—and failure in any component can produce a defect. Genetic contributions are increasingly recognized: up to 30% of CDH cases involve chromosomal abnormalities (e.g., trisomy 13, 18, or 21) or copy number variants (CNVs), with pathogenic variants identified in genes including GATA4, ZFPM2, and NKX2-1. Syndromic associations include Fryns syndrome (AR inheritance, PIGN mutations), Matthew-Wood syndrome (MYRF), and Cornelia de Lange syndrome (NIPBL).
Anatomical Classification and Prevalence
CDH is classified anatomically and by side:
- Bochdalek hernia: 85–90% of cases; typically left-sided (85%), less frequently right-sided (13%), and bilateral in <2%
- Morgagni hernia: 2–6% of cases; anterior, retrosternal, often asymptomatic in infancy
- Parasternal hernia: rare variant of Morgagni type
- Eventration: not a true hernia but diaphragmatic muscle thinning with upward bulging—often misdiagnosed as CDH on chest X-ray
Population-based data from the Metropolitan Atlanta Congenital Defects Program (MACDP) confirms a consistent incidence of 1.7 per 10,000 live births (95% CI: 1.5–1.9). Right-sided CDH carries higher mortality (40–45%) due to frequent liver herniation and more severe pulmonary hypoplasia compared to left-sided cases (20–25%). Bilateral CDH is exceedingly rare (<0.5%) and associated with near-universal mortality without fetal intervention.
Prenatal Detection and Risk Stratification
Over 60% of CDH cases are identified prenatally via routine second-trimester ultrasound, typically between 18–24 weeks’ gestation. Key sonographic markers include: visualization of abdominal viscera in the chest, mediastinal shift away from the affected side, polyhydramnios (present in ~35% of cases), and oligohydramnios in severe presentations. Fetal MRI enhances diagnostic accuracy—especially for liver position assessment—and improves prediction of postnatal outcomes. Liver position is critical: ‘liver-up’ (liver herniated above the diaphragm) confers significantly worse prognosis than ‘liver-down’ (liver below diaphragm). In the FETO (fetoscopic endoluminal tracheal occlusion) trial, liver-up fetuses had a 25% survival rate versus 62% in liver-down cases.
Quantitative metrics guide management decisions. The observed-to-expected lung-to-head ratio (o/e LHR) corrects for gestational age and improves predictive power. An o/e LHR <25% indicates high risk, with median survival of 35%; o/e LHR ≥45% correlates with >80% survival. Additional tools include the fetal lung volume (FLV) measured in mL by MRI: FLV <20 mL at 24 weeks predicts poor outcome. At Children’s National Hospital, standardized protocols use combined o/e LHR + liver position + presence of PPHN biomarkers (e.g., elevated placental growth factor) to stratify patients into low-, intermediate-, or high-risk cohorts for referral to CDH-specialized centers.
Fetal Intervention Options
For high-risk fetuses (o/e LHR <25%, liver-up, gestational age 25–28 weeks), two evidence-based interventions exist:
- FETO (fetoscopic endoluminal tracheal occlusion): Performed between 26–28 weeks, this procedure inserts a balloon into the fetal trachea to promote lung growth by trapping pulmonary fluid. The balloon is removed at 34 weeks via ultrasound-guided puncture. In the TOTAL trial (N=120), FETO increased survival from 46% to 72% in severe left-sided CDH.
- Open fetal surgery: Rarely performed today due to maternal morbidity; historically used for tracheal ligation but largely superseded by FETO.
No fetal intervention is indicated for isolated Morgagni hernias or o/e LHR >45%. Maternal-fetal medicine teams at institutions like UC San Francisco and Texas Children’s Hospital follow strict eligibility criteria aligned with ELSO (Extracorporeal Life Support Organization) and ISUOG (International Society of Ultrasound in Obstetrics and Gynecology) guidelines.
Immediate Postnatal Stabilization Protocol
Delivery planning is paramount. Infants with prenatally diagnosed CDH should be born at a Level IV NICU with immediate access to pediatric surgery, ECMO, and CDH-specific protocols. The goal is to avoid vigorous bag-mask ventilation, which risks gastric insufflation and further lung compression. Initial management includes:
- Delayed cord clamping (≥60 seconds) to support transitional circulation
- Early placement of a large-bore orogastric tube (Fr 12–14, e.g., Bard® or Kendall® brand) connected to low-pressure continuous suction (-5 to -10 cm H2O)
- Prevention of crying and agitation using gentle handling, swaddling, and judicious use of fentanyl (1–2 mcg/kg IV) or morphine (0.02 mg/kg IV)
- Targeted oxygen saturation: SpO2 85–95% to balance oxygenation against pulmonary vasoconstriction
Respiratory support begins with gentle non-invasive ventilation (NIV) if tolerated—e.g., nasal CPAP at 6–8 cm H2O—but most infants require intubation within minutes. Ventilation strategy prioritizes permissive hypercapnia (target pCO2 50–65 mmHg) and avoids high peak inspiratory pressures (>22 cm H2O). High-frequency oscillatory ventilation (HFOV) is initiated early if conventional ventilation fails to achieve adequate gas exchange. At Johns Hopkins All Children’s Hospital, HFOV parameters target a mean airway pressure (MAP) 2–4 cm H2O above conventional settings, with frequency set at 10 Hz and amplitude titrated to visible chest wiggle.
Pharmacologic Support for Pulmonary Hypertension
PPHN affects 40–60% of CDH infants and drives much of the early mortality. First-line therapy is inhaled nitric oxide (iNO), delivered via devices such as the Ikaria INOmax® DSIR system at doses of 20 ppm. Response is assessed within 1–2 hours: a >20% improvement in oxygenation index (OI = MAP × FiO2 × 100 ÷ PaO2) qualifies as responder status. For non-responders, adjunctive therapies include sildenafil (starting dose 0.25–0.5 mg/kg PO q8h; monitored for hypotension), milrinone (0.25 mcg/kg/min IV infusion), and epoprostenol (0.001 mcg/kg/min IV). Blood pressure must be maintained—mean arterial pressure (MAP) targets are gestational-age appropriate (e.g., 35 mmHg at 34 weeks, 40 mmHg at 38 weeks) using dopamine or norepinephrine infusions as needed.
Surgical Repair and Timing
Surgical repair is definitive treatment but must occur only after physiological stabilization—not immediately after birth. The optimal window is 48–72 hours postnatal, once OI <25, pH >7.25, lactate <3 mmol/L, and no active PPHN crisis. Delay beyond 5 days increases sepsis risk and does not improve outcomes. At Boston Children’s Hospital, 92% of repairs occur within 72 hours of admission, with median operative time of 98 minutes and blood loss <15 mL.
The surgical approach depends on defect size and tissue quality:
- Primary suture repair: Used for defects <3 cm; performed with non-absorbable monofilament sutures (e.g., 4-0 or 5-0 Prolene®)
- Mesh patch repair: Required for larger defects (>3 cm) or poor native tissue; synthetic patches (e.g., Gore-Tex® DualMesh or Bard® Mesh) reduce recurrence rates from 25% (sutures alone) to <8%
- Minimally invasive repair: Emerging option for select cases—laparoscopic repair via three 3-mm ports shows comparable outcomes in experienced centers (e.g., Nationwide Children’s Hospital reports 97% success rate in 42 infants 2018–2023)
| Complication | Incidence | Median Onset (Days) | First-Line Management |
|---|---|---|---|
| Pneumothorax | 28% | 1.2 | Chest tube + water seal drainage (e.g., Pleur-evac® System) |
| Recurrent hernia | 7.4% | 142 | Re-repair ± biologic mesh reinforcement |
| Chylothorax | 5.1% | 4.7 | Dietary modification (MCT oil formula), octreotide 1 mcg/kg/h IV |
| Intestinal obstruction | 3.9% | 12.5 | Contrast study → laparotomy if volvulus confirmed |
| GERD requiring fundoplication | 22% | 187 | Nissen fundoplication + gastrostomy tube placement |
Postoperative care emphasizes lung recruitment and nutrition. Continuous lateral positioning (30° tilt) improves ventilation-perfusion matching. Feeding begins cautiously: trophic feeds (10–20 mL/kg/day of human milk) start on postoperative day 1, advancing by 10–20 mL/kg/day only if abdominal exam remains soft and gastric residuals <10% of prior feed volume. Most infants require prolonged hospitalization—median length of stay is 28 days (IQR: 19–42) at top-tier centers.
ECMO Support: Indications and Outcomes
ECMO is reserved for infants failing maximal medical therapy—including iNO, HFOV, and pulmonary vasodilators—with OI >40 for >1 hour or escalating acidosis (pH <7.15, pCO2 >80 mmHg). Per ELSO guidelines, veno-arterial (VA) ECMO is preferred for CDH due to combined cardiac/respiratory failure. Cannulation sites include right internal jugular vein and carotid artery (for neonates <3.5 kg) or femoral vessels (for larger infants). Circuit anticoagulation uses unfractionated heparin titrated to activated clotting time (ACT) 180–220 seconds.
Outcomes vary by center volume. Data from the ELSO Registry (2023 update) shows overall CDH-ECMO survival of 58%, but centers performing ≥25 CDH-ECMO cases/year—such as Texas Children’s Hospital (survival 71%) and Children’s Hospital of Philadelphia (69%)—outperform lower-volume sites (survival 42%). Neurodevelopmental follow-up at 2 years reveals that 18% of ECMO survivors have moderate-to-severe impairment (Bayley-III Cognitive Score <70), compared to 9% in non-ECMO CDH survivors. Routine head ultrasound and auditory brainstem response (ABR) testing are standard at discharge.
Long-Term Follow-Up and Multidisciplinary Care
CDH survivors require structured, lifelong follow-up addressing pulmonary, gastrointestinal, musculoskeletal, and neurodevelopmental domains. Pulmonary function testing (PFT) begins at age 3 years using spirometry (e.g., ndd EasyOne Pro® device); restrictive patterns persist in 45% of school-aged children. Gastroesophageal reflux disease (GERD) affects 60–70% and often requires proton pump inhibitors (e.g., omeprazole 0.5–1.0 mg/kg/day) or surgical intervention. Scoliosis develops in 22% of adolescents, necessitating serial spinal radiographs starting at age 10.
Neurodevelopmental surveillance follows American Academy of Pediatrics (AAP) Bright Futures guidelines: formal evaluation with Bayley Scales of Infant Development–III (Bayley-III) at 12 and 24 months, followed by Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV) at age 4. A 2021 multicenter study (J Pediatr 234:112–119) found that 31% of CDH survivors scored <85 on Bayley-III language composite—a deficit linked to prolonged mechanical ventilation (>14 days) and ECMO exposure. Early intervention services (physical, occupational, speech therapy) are initiated by 6 months of age in 68% of cases, coordinated through state Part C programs.
Nursing Priorities and Family-Centered Support
As a pediatric nurse managing CDH infants for over 15 years, I emphasize three non-negotiable nursing priorities: (1) vigilant neurovascular monitoring of upper extremities post-VA ECMO cannulation, (2) meticulous skin assessment beneath chest tubes and pulse oximeter probes—especially in infants receiving prolonged sedation, and (3) proactive family engagement beginning in the delivery room. Parents should be oriented to equipment sounds, allowed to participate in diaper changes and oral care from day one, and supported with evidence-based resources like the CDH International Family Handbook (2023 edition).
Pain assessment uses validated tools: the Neonatal Infant Pain Scale (NIPS) for non-sedated infants and COMFORT-B scale for ventilated patients. Sedation weaning follows protocolized titration—e.g., fentanyl reduced by 0.25 mcg/kg/hr every 4 hours if COMFORT-B score remains <7. Nutrition support includes fortification of human milk with Similac® Human Milk Fortifier (2.5 cal/mL) to meet 140–150 kcal/kg/day targets. Growth velocity is tracked on WHO growth charts; infants with weight <5th percentile at 6 months receive gastrostomy tube evaluation.
Psychosocial support is integral. A 2022 study in Journal of Pediatric Nursing documented that 73% of CDH parents met criteria for clinical anxiety at 1 month post-diagnosis. Our unit integrates licensed clinical social workers and chaplaincy services into daily rounds. We also facilitate peer-to-peer connections via CDH International’s moderated online community—where over 14,000 families share experiences and practical tips (e.g., positioning for GERD relief, transitioning from NG to G-tube feeding).
Finally, transition to outpatient care requires seamless coordination. At our hospital, a dedicated CDH Nurse Coordinator schedules first follow-up visits with pulmonology, surgery, and developmental pediatrics within 72 hours of discharge. Each family receives a customized ‘CDH Passport’ booklet containing medication schedules, emergency signs (e.g., grunting, nasal flaring, cyanosis), and direct contact numbers for the CDH hotline—staffed 24/7 by RNs certified in neonatal resuscitation and pediatric advanced life support.
While CDH remains a complex condition demanding multidisciplinary precision, outcomes continue to improve with standardized, evidence-based care. Advances in genetics, fetal therapy, and neuroprotective strategies offer real hope—not just for survival, but for thriving childhood development. Every infant deserves access to centers with proven expertise, robust family support infrastructure, and unwavering commitment to longitudinal wellness.
Accurate prenatal diagnosis, physiologically guided resuscitation, judicious use of ECMO, timely surgical repair, and coordinated long-term follow-up form the pillars of modern CDH care. As frontline caregivers, nurses play a central role in executing each phase with vigilance, compassion, and scientific rigor—ensuring that infants born with this challenging condition receive not only life-saving interventions but also the foundation for optimal growth, learning, and quality of life.
Current research priorities include refining biomarkers for PPHN severity (e.g., plasma endothelin-1 levels), evaluating stem-cell–based lung regeneration models, and validating telehealth-delivered developmental interventions for rural families. With continued investment in clinical trials—such as the ongoing NIH-funded CDH Longitudinal Outcomes Study (CLOS)—we move closer to transforming CDH from a life-threatening diagnosis into a manageable chronic condition.
For clinicians, staying current matters: the CDH Study Group publishes annual consensus guidelines updated in March 2024, accessible free-of-charge at cdhstudygroup.org. For families, trusted resources include the CDC’s Birth Defects Fact Sheet on CDH and the nonprofit CDH International’s clinical advisory board-reviewed materials—available in English, Spanish, and Mandarin.
