Maternal hyperoxygenation in congenital heart disease

Abstract

The importance of prenatal diagnosis and fetal intervention has been increasing as a preventative strategy for improving the morbidity and mortality in congenital heart disease (CHD). The advancements in medical imaging technology have greatly enhanced our understanding of disease progression, assessment, and impact in those with CHD. In particular, there has been a growing focus on improving the morbidity and mortality of fetuses diagnosed with left-sided lesions. The disruption of fetal hemodynamics resulting from poor structural developmental of the left outflow tract during cardiogenesis is considered a major factor in the progressive lethal underdevelopment of the left ventricle (LV). This positive feedback cycle of inadequate flow and underdevelopment of the LV leads to a disrupted fetal circulation, which has been described to impact fetal brain growth where systemic outflow is poor and, in some cases, the fetal lungs in the setting of a restrictive interatrial communication. For the past decade, maternal hyperoxygenation (MH) has been investigated as a diagnostic tool to assess the pulmonary vasculature and a therapeutic agent to improve the development of the heart and brain in fetuses with CHD with a focus on left-sided cardiac defects. This review discusses the findings of these studies as well as the utility of acute and chronic administration of MH in CHD.

Hypoplastic Left Heart Syndrome: Is There a Role for Fetal Therapy?

“…Altogether, as summarized previously, chronic MH may have beneficial effects on left heart growth (70). In presence of left to right shunting at the atrial level these effects may be limited only to those patients with a somewhat restrictive interatrial communication, but there is no data yet to support this hypothesis.…”

“…Chronic MH should be initiated at about 50% FiO2 for at least 9 h per day with only few interruptions to avoid repeated changes in fetal hemodynamics (16,70).…”

Advances in the Prenatal Management of Fetal Cardiac Disease

“…A systematic review of the current literature by Co-Vu et al found that most protocols used 8 L with 100% oxygen by a non-rebreather at a mean gestational age of 33.4 weeks [ 29 ]. The duration of therapy ranges from 10 min in a single session to 3–4 h per day [ 30 ].…”

“…The data presented in this study are openly available in reference number [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ].…”

Hypoplastic Left Heart Syndrome Across the Lifespan: Clinical Considerations for Care of the Fetus, Child, and Adult

“…In patients with HLHS, this manoeuvre can be used to gauge pulmonary vasodilatory capacity, which is significantly reduced in patients with atrial septal restriction and thus can identify patients with abnormal pulmonary vascularity who may prove to be poor candidates for fetal intervention. [38][39][40] In addition, acute maternal hyperoxygenation may facilitate identification of fetuses who may need urgent atrial septostomy after birth. A logical extension would be to determine whether chronic maternal hyperoxygenation could potentially affect left heart growth by increasing flow though the left-side structures.…”