Cardiovascular Response to Maternal Hyperoxygenation in Fetal Congenital Heart Disease

The purpose of this study is to investigate the phenomenon of cardiovascular system response to maternal hyperoxygenation in the fetus with congenital heart disease(CHD), which can provide further insight into fetal adaptations to CHD and improve our understanding of the pathophysiology of these conditions.Cases are gravidas with fetal congenital heart disease diagnosed by echocardiography various gestational weeks.The baseline fetal echocardiography parameters has obtained from these gravidas.Then the participants received 10-15 minutes hyperoxygenation, and the accordingly fetal echocardiography parameters were obtained.The objective of the study includes:(1)To investigate the response of the MCA PI to maternal hyperoxygenation in various forms of CHD. Middle cerebral artery(MCA) pulsatility index (PI) at MH will be compared to baseline at various gestational ages in a variety of types of CHD;(2)To investigate the response of the umbilical artery (UA) PI to maternal hyperoxygenation in various forms of CHD. UA PI at MH will be compared to baseline at various gestational ages in a variety of CHD; (3)To study the response of myocardial diastolic function to MH in various forms of CHD. Diastolic inflow patterns across the tricuspid and mitral valves will be measured and ductus venosus flow pattern will be evaluated at MH and compared to baseline at various gestational ages in a variety of CHD;(4)To investigate for any changes in cardiac output and the ratio of flow between the right and left ventricles in response to MH in various forms of CHD;(5)To investigate for changes in flow pattern at the aortic isthmus in those with suspicion or clear evidence of coarctation of the aorta.

Maternal hyperoxygenation will be offered by administering 10 liters nasal cannula by face-mask (approximately 60% fiO2) for a minimum of 10 minutes.

The response of the MCA PI to maternal hyperoxygenation in various forms of CHD. MCA PI at MH will be compared to baseline at various gestational ages in a variety of types of CHD.

Response of the umbilical artery (UA) PI to maternal hyperoxygenation in various forms of CHD. UA PI at MH will be compared to baseline at various gestational ages in a variety of CHD.

Diastolic inflow patterns across the tricuspid and mitral valves will be measured and ductus venosus flow pattern will be evaluated at MH and compared to baseline at various gestational ages in a variety of CHD.

any changes in cardiac output and the ratio of flow between the right and left ventricles in response to MH in various forms of CHD.

Changes in flow pattern at the aortic isthmus in those with suspicion or clear evidence of coarctation of the aorta

Inclusion Criteria: All singleton fetuses with CHD at all gestational ages are eligible for enrollment in the study. Patients will be recruited to enroll in the study as they present for clinical care at Fetal Echocardiography clinic. MH assessments will all be performed only at the Beijing Anzhen Hospital. Baseline room air data for CHD may be collected from other referring centers within the Anzhen network. Exclusion Criteria: Non-sinus rhythm, presence of arrhythmia; Fetal hydrops; Severe brain anomaly (which may influence MCA flow); Evidence for significant ventricular dysfunction; Evidence for constriction of the ductus arteriosus