Effects of maternal hyperoxygenation in a case of severe congenital diaphragmatic hernia accompanied by hydrops fetalis

We report a case of severe congenital diaphragmatic hernia accompanied by hydrops fetalis in a fetus conceived by a 33-year-old woman. Fetal magnetic resonance imaging performed at 27 weeks of gestation revealed herniation of the stomach, bowel, and left liver into the thoracic cavity, confirming severe left-sided CDH. Presence of hydrops fetalis at 32 weeks of gestation and its progression over the next 2 weeks was confirmed by fetal echography. Subsequently, fetal echocardiography revealed severe tricuspid regurgitation and reverse flow in the inferior vena cava at 33 weeks, with abnormal left and right ventricular Tei indices, extended left ventricular isovolumetric relaxation time, and increased preload index. Maternal hyperoxygenation (MHO) therapy was initiated at 35 weeks of gestation to increase pulmonary blood flow and promote venous return to the left ventricle. The hydrops was attenuated by MHO for 2 weeks, and fetal echocardiography demonstrated improved cardiac performance. A female infant was born at 37 weeks of gestation and underwent diaphragmatic repair shortly after birth. She survived surgery and was discharged at 4 months of age with no adverse sequelae. This case report suggests that MHO may be a potential therapy for severe congenital diaphragmatic hernia associated with hydrops fetalis.