ECMO for COVID-19 in pregnancy

ECMO for COVID-19 in pregnancy | Image Credit: © sebra - © sebra - stock.adobe.com.

According to a recent study published in JAMA Network Open, pregnant and post partum patients requiring extracorporeal membrane oxygenation (ECMO) will rarely experience mortality but will often experience severe maternal morbidity.

COVID-19 infection during pregnancy has been associated with increased risk of severe disease compared to COVID-19 outside of pregnancy, with severe disease reported in 5% to 12% of pregnant patients with COVID-19. Increased risks of hypertensive disorders of pregnancy, preterm birth, critical care interventions, and venous thromboembolism have also been reported.

ECMO is often used as salvage therapy in pregnant or post partum patients with acute respiratory distress syndrome and refractory hypoxemia or cardiac failure. Studies on ECMO use in patients with COVID-19 have reported conflicting data on maternal mortality.

To determine maternal and perinatal outcomes from ECMO use in pregnant or post partum patients with COVID-19, investigators conducted a retrospective cohort study. Patient data was gathered from 25 US hospitals affiliated with 1 of 22 centers throughout the United States. 

Of the hospitals, 23 were associated with academic medical centers, while 1 was a community hospital and another a military hospital. Patients were included if they were given a positive COVID-19 diagnosis during pregnancy or within 6 weeks post partum based on an antigen test or a positive nucleic acid and started ECMO between March 1, 2020, and October 1, 2022.

Extracted data included obstetrical, sociodemographic, maternal, and perinatal outcomes. Electronic health records were consulted for race and ethnicity data, while the Social Vulnerability Index was determined using primary residence zip codes.

Maternal mortality, defined as maternal death while on ECMO or within 30 days of discharge, was measured as the primary outcome of the study. Serious maternal morbidity events were measured as secondary outcomes, along with obstetric and neonatal outcomes.

Maternal morbidity events included ischemic stroke or intracranial hemorrhage, venous thromboembolism, limb ischemia, gastrointestinal bleeding, acute kidney injury, cardiac complications, liver failure, and ischemic injury.

Research Electronic Data Capture was used to gather and manage data, with data checks performed by the primary investigator. The timing of ECMO initiation relative to pregnancy status, defined as pregnancy or post partum stage, were used to compare outcomes.

There were 1000 pregnant or post partum patients given ECMO for respiratory failure because of COVID-19 during the study period, 29% of which were Hispanic, 25%, non-Hispanic Black, and 34% non-Hispanic White. Of patients, 47 were pregnant, 21 within 24 hours post partum, and 32 between 24 hours and 6 weeks post partum.

Patients were aged a mean 31.1 years, 79% had obesity, 61% had public or no insurance, and 67% were not immunocompromised. Prior vaccination was reported in 4 patients, of which 2 had no severe morbidity events and the other 2 had venous thromboembolism.

ECMO had a median reported run of 20 days and was injected at a median 25.1 weeks’ gestation in pregnant patients. Sixteen maternal deaths were reported in the study cohort, though the rates of mortality did not significantly differ based on pregnancy status.

One or more severe maternal morbidity even was seen in 76% of patients, with venous thromboembolism being the most common event in 39% of patients. Variation in ischemic injuries were seen based on pregnancy status, in 18.9% of post partum patients compared to 4.3% of pregnant patients. 

Other morbidity events saw similar rates based on pregnancy status. Neonatal outcomes also did not differ based on pregnancy status, with the exception of higher bronchopulmonary dysplasia rates in offspring of mothers receiving ECMO immediatelypost partum and slightly increased birth weight in offspring of mothers who received ECMO post partum.

Overall, low mortality rates but high morbidity rates were observed in pregnant or post partum patients receiving ECMO for COVID-19. Doctors should be prepared for morbidity outcomes when administering ECMO in this population.

Reference

Byrne JJ, Shamshirsaz AA, Cahill AG, et al. Outcomes following extracorporeal membrane oxygenation for severe COVID-19 in pregnancy or post partum. JAMA Netw Open. 2023;6(5):e2314678. doi:10.1001/jamanetworkopen.2023.14678