Considerations in pregnant individuals with low baseline oxygen saturation: a response

We would like to thank the authors for their comments on our recent publication.¹ We agree that it is very important to interpret the oxygen saturation in the setting of underlying maternal disease. Targeting a higher oxygen saturation in pregnancy in certain patients with baseline low levels of oxygen is not always feasible from a physiological standpoint. In addition to patients with a hemoglobinopathy described by the authors, other populations with congenital cyanotic heart disease, such as Eisenmenger syndrome, have decreased oxygen saturation in the systemic circulation.² Maternal oxygen saturation in these patients should be assessed and optimized throughout the pregnancy to avoid adverse maternal and fetal outcomes. Hence, determining the baseline maternal parameters (including oxygen saturation) at the beginning of the pregnancy is crucial for guiding management, especially during this COVID-19 pandemic.