Congenital diaphragmatic hernia: does gestational age at diagnosis matter when evaluating morbidity and mortality?

Objective: The objective of the investigation was to study the relationship between gestational age at diagnosis and mortality and morbidity in fetuses with an isolated congenital diaphragmatic hernia.

Study Design: Between January 2008 and November 2013, 377 live births with isolated congenital diaphragmatic hernia diagnosed antenatally at a known gestational age were recorded in the database of the French National Center for Rare Diseases. The primary outcome studied was mortality estimated at 28 days and at 6 months. The secondary outcome was morbidity evaluated by pulmonary arterial hypertension at 48 hours, oxygen therapy dependence at 28 days, oral disorders, enteral feeding, and prosthetic patch repair. Analyses were adjusted for the main factors of congenital diaphragmatic hernia severity (side of the hernia, thoracic herniation of the liver, gestational age at birth, lung-to-head ratio, and prenatal treatment by tracheal occlusion.

Results: Mortality rates at 28 days decreased significantly (P < .001) when gestational age at diagnosis increased: 61.1%, 39.2%, and 10.4% for a diagnosis in the first, second, and third trimester, respectively. Adjusted odds ratios were 3.12 [95% confidence interval, 1.86-5.25] and 0.35 [95% confidence interval, 0.18-0.66] for a diagnosis in the first and third trimesters, respectively, compared with a diagnosis in the second trimester. Similarly, morbidity decreased significantly when gestational age at diagnosis increased, and the trend remained significant after adjustment for the main factors of congenital diaphragmatic hernia severity (P < .001).

Conclusion: Gestational age at diagnosis is an independent predictor of postnatal prognosis for children presenting an isolated congenital diaphragmatic hernia and should be taken into account when estimating postnatal morbidity and mortality.