Outcomes of Critically Ill Pregnant Women with COVID-19 in the United States

Data from viral respiratory illnesses such as influenza, severe acute respiratory syndrome coronavirus 1, and Middle East respiratory syndrome suggest that viral respiratory infection during pregnancy may worsen both maternal and fetal outcomes (1, 2). Existing data in critically ill pregnant women with coronavirus disease (COVID19) are mainly limited to case series or systematic reviews lacking nonpregnant control subjects (3–5). To better understand this potentially at-risk population, we describe the clinical course of 32 critically ill pregnant women admitted to ICUs across the United States. Furthermore, we compare the characteristics, treatment, and outcomes of these pregnant women with those of women who were not pregnant at the time of ICU admission. We used data from STOP-COVID (Study of the Treatment and Outcomes in Critically Ill Patients with COVID-19), a multicenter cohort study of critically ill adults with laboratory-confirmed COVID-19 admitted to 67 participating ICUs across the United States (6). For the current analysis, we included all COVID19–positive pregnant women admitted to ICUs between March 4 and May 2, 2020. We matched each pregnant woman with two nonpregnant women according to age (62 yr) and the Quick Sequential Organ Failure Assessment (qSOFA) score at admission to the ICU (7). For purposes of matching, we dichotomized the qSOFA score into lower risk (score of 0–1) and higher risk (score of 2–3). All patients were followed up until hospital discharge, death, or a minimum of 28 days after ICU admission. We compared outcomes between pregnant and nonpregnant women using chisquare or Fisher exact tests for categorical variables and the Wilcoxon rank-sum test for continuous variables. Among 4,145 patients in the parent cohort, we identified 32 pregnant women andmatched these to 64 nonpregnant women. The median age in both groups was 32 years (interquartile range, 27–35). In both groups, 62.5% of patients had a qSOFA score of 2 or 3 at admission. The frequency and severity of acute respiratory failure, assessed by receipt of invasive mechanical ventilation and the PaO2/FIO2 ratio at ICU admission, were similar between groups (Table 1). Pregnant women were more likely to receive remdesivir (50.0% vs. 10.9%) and less likely to receive tocilizumab than nonpregnant women (9.4% vs. 23.4%). The rate of invasive mechanical ventilation, prone positioning, and neuromuscular blockade during the 14 days after ICU admission was similar between groups. The incidences of venous thromboembolism and other acute organ injuries, together with ICU and hospital length of stay, were similar between groups (Table 1). There were no maternal or fetal deaths, whereas 6 of the 64 nonpregnant women (9.4%) died during hospitalization. A total of 19 women (59.3%) delivered during the hospitalization, with 11 of the 19 deliveries (57.9%) occurring on the day of ICU admission. Among the 19 deliveries, 18 (94.7%) were preterm, defined as occurring at less than 37 weeks’ gestation. Only three of these preterm births were spontaneous, with the remainder performed for medical or obstetric indications. The most common indications for delivery were maternal respiratory failure (52.6%), spontaneous labor or rupture of membranes (25.0%), and nonreassuring fetal status (21.1%) (Table 2). A total of 17 of the 19 women (89.5%) who delivered underwent cesarean section, with maternal critical illness reported as the most common indication (41.2%). Among the 17 women with pregnancies at more than 30 weeks’ gestation at ICU admission, 15 (88.2%) delivered, as compared with 4 out of 15 (26.7%) who delivered at less than 30-weeks’ gestation. Unlike prior viral pandemics (1–4), maternal and fetal outcomes among critically ill pregnant women with COVID-19 in our cohort were excellent, with no reported deaths. Consistent with prior COVID-19 studies in pregnant women, our study found high rates of cesarean delivery and preterm birth (3–5). The majority of preterm delivery occurred in the setting of maternal respiratory failure, with a high rate of cesarean delivery for this indication. Complex medical decision-making is required in the management of critically ill pregnant women. The decision regarding delivery needs to balance multiple risks and benefits, including the risks of prematurity to the fetus, the potential to improve or worsen maternal respiratory status with delivery, and the known maternal hemodynamic and inflammatory burden accompanying major surgery such as cesarean section (8). Pregnant women in our cohort at less than 30-weeks’ gestation at the time of ICU admission were less likely to undergo delivery, which may reflect attempts to maximize fetal survival. Pregnant women in our cohort had lower mortality than ageand qSOFA-matched nonpregnant women. This finding may reflect the lower burden of comorbidities among pregnant women in our small cohort. Notably, a recently published case series from Iran reported a high rate of mortality (77.8%) among nine critically ill pregnant women with COVID-19 (9). Potential reasons for the vastly different outcomes observed in the pregnant women in our cohort include differences in healthcare delivery systems, patient risk factors, and an apparently low threshold for ICU admission for pregnant patients with COVID-19 in our cohort. We followed patients until hospital discharge, but our cohort lacks long-term follow-up data, including neonatal outcomes. Both pregnancy and COVID-19 raise the risk of thromboembolic disease, highlighting the need for long-term follow-up data in pregnant and postpartum women with COVID-19. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/). For commercial usage and reprints, please contact Diane Gern (dgern@thoracic.org).