Both vaginal and cesarean deliveries have been reported in pregnant patients on ECMO support.[1,22] Decisions around fetal monitoring and obstetric interventions are individualized with consideration of gestational age, fetal lung maturity, likelihood of maternal cardiopulmonary recovery, anticipated ECMO duration, as well as fetal and maternal comorbidities. Antenatal corticosteroids for fetal lung maturity are given between viability and 34 weeks.[18,23] At our institution, we typically commence around-the-clock, continuous external fetal monitoring as early as 24 weeks for critically ill patients, with a dedicated labor nurse at the patient's bedside for fetal heart rate interpretation and appropriate intervention. Maternal sedative-hypnotic medications predictably reduce fetal heart rate variability. In the event of acutely nonreassuring fetal heart rate tracing (eg, bradycardia or recurrent decelerations), reversible causes such as maternal hypoxemia, hypotension, aortocaval compression, inadequate ECMO settings, circuit thrombosis, or cannula malposition must be quickly identified and corrected. Persistently abnormal tracings or maternal cardiopulmonary instability often warrant urgent delivery, so in-house high-risk obstetrics coverage is required, and instruments for delivery must be immediately available in the intensive care unit (ICU). Other methods of fetal assessment, including serial biophysical profiles and ultrasound growth assessments, are also performed to identify fetal compromise necessitating delivery.
In the absence of obstetric indications, elective preterm delivery during critical illness is controversial. If there is ongoing maternal cardiopulmonary dysfunction, it may be desirable to plan for elective vaginal or, more likely, cesarean delivery under controlled conditions to mitigate the potential for later emergent delivery due to fetal heart rate abnormalities. Yet, prematurity is associated with neonatal morbidity and mortality, and early delivery does not guarantee improved maternal outcomes.[24–26] Additionally, cesarean delivery is a major surgery with considerable maternal inflammatory burden and risks of hemorrhage, hemodynamic instability, or infection. Prior reports have also demonstrated the feasibility of pregnancy maintenance for several weeks during ECMO support.[1,18,27] Balancing the risks to mother and fetus, it is reasonable to aim for a goal of 28 to 32 weeks gestation for delivery timing.[28,29] Ultimately, it is the team's decision to consider all relevant factors before undertaking cesarean delivery while on ECMO.
Anesth Analg. 2022;135(2):277-289. © 2022 International Anesthesia Research Society