Can a subchorionic hemorrhage (subchorionic hemorrhage) cause a congenital diaphragmatic hernia (CDH) and are there any prenatal treatments or interventions, such as intrauterine or fetal surgery, that can correct the hernia?

Congenital Diaphragmatic Hernia: Causes, Prenatal Management, and Surgical Options

A subchorionic hemorrhage does not cause congenital diaphragmatic hernia (CDH), as CDH develops during early embryonic development around the 8th week of gestation due to incomplete formation of the diaphragm. 1 The diaphragmatic hernia diagnosed at 20 weeks was likely already present before the subchorionic hemorrhage was identified at 15 weeks.

Etiology of Congenital Diaphragmatic Hernia

CDH is a developmental defect that occurs during early embryonic formation:

• Develops during the 8th week of gestation when the diaphragm fails to form completely 1
• Most commonly presents as a Bochdalek hernia (95% of cases), typically on the left side (80-85%) 1, 2
• Results in abdominal organs entering the thoracic cavity, causing pulmonary hypoplasia 1
• Not caused by maternal bleeding events like subchorionic hemorrhage

Diagnosis and Assessment

The diagnosis of CDH at 20 weeks through anatomy scan is consistent with standard practice:

• CT scan is the gold standard for diagnosing diaphragmatic abnormalities in adults, but prenatal ultrasound is the primary diagnostic tool during pregnancy 1, 2
• The finding of intestines in the chest cavity pushing the heart to the right side indicates a severe form of CDH 3
• Severity assessment includes evaluation of:
  • Lung size/volume
  • Liver position (herniation into chest indicates worse prognosis)
  • Degree of pulmonary hypoplasia 3, 4

Prenatal Treatment Options

Fetoscopic Endoluminal Tracheal Occlusion (FETO) is a proven prenatal intervention that could have been considered for this severe CDH case: 3

• FETO involves placing a balloon in the fetal trachea to promote lung growth
• Level I evidence shows FETO increases survival to discharge in selected cases 3
• Typically offered for severe cases with poor predicted outcomes 5
• The procedure has shown a 50% survival rate in severe cases 5
• Timing of the procedure is critical for balancing benefits against risks of prematurity 3

Management of Subchorionic Hemorrhage

Regarding the subchorionic hemorrhage at 15 weeks:

• Standard management typically includes monitoring and sometimes activity restriction
• There is no evidence that specific interventions for subchorionic hemorrhage would have prevented or affected the CDH 1
• The hemorrhage and the CDH are unrelated conditions, as the diaphragm forms much earlier in development

Postnatal Surgical Management

Had the pregnancy continued, postnatal management would have included:

• Immediate intubation and ventilation in a tertiary care center 1
• Surgical repair of the diaphragmatic defect:
  • Minimally invasive approach (laparoscopic) for stable patients 2
  • Open surgical approach for unstable patients 2
  • Use of non-absorbable sutures for small defects (<8 cm) 2
  • Mesh reinforcement for larger defects (>8 cm) 2

Prognosis and Outcomes

The severity of this case (intestines in chest, cardiac displacement) suggests a challenging prognosis:

• Higher risk features include:
  • Liver herniation into chest
  • Need for patch repair
  • Potential need for extracorporeal membrane oxygenation (ECMO) 4
• Prenatal diagnosis and management in specialized centers can improve outcomes despite higher risk factors 4
• Survival rates vary significantly based on severity, with overall survival around 73% in centers with multidisciplinary perinatal management 4

Key Points for Patient Counseling

• CDH is a developmental defect that occurs early in pregnancy, unrelated to the subchorionic hemorrhage
• For severe cases like this, prenatal intervention with FETO could have been considered at specialized centers
• Optimal management requires delivery at a tertiary care center with immediate neonatal support
• Outcomes depend on severity factors, with specialized centers achieving better results even in high-risk cases