SARS-CoV-2 Infection Among Hospitalized Pregnant Women: Reasons for Admission and Pregnancy Characteristics

Eight U.S. Health Care Centers, March 1-May 30, 2020

Lakshmi Panagiotakopoulos, MD; Tanya R. Myers, PhD; Julianne Gee, MPH; Heather S. Lipkind, MD; Elyse O. Kharbanda, MD; Denison S. Ryan, MPH; Joshua T.B. Williams, MD; Allison L. Naleway, PhD; Nicola P. Klein, MD, PhD; Simon J. Hambidge, MD, PhD; Steven J. Jacobsen, MD, PhD; Jason M. Glanz, PhD; Lisa A. Jackson, MD; Tom T. Shimabukuro, MD; Eric S. Weintraub, MPH


Morbidity and Mortality Weekly Report. 2020;69(38):1355-1359. 

In This Article

Abstract and Introduction


Pregnant women might be at increased risk for severe coronavirus disease 2019 (COVID-19), possibly related to changes in their immune system and respiratory physiology*.[1] Further, adverse birth outcomes, such as preterm delivery and stillbirth, might be more common among pregnant women infected with SARS-CoV-2, the virus that causes COVID-19.[2,3] Information about SARS-CoV-2 infection during pregnancy is rapidly growing; however, data on reasons for hospital admission, pregnancy-specific characteristics, and birth outcomes among pregnant women hospitalized with SARS-CoV-2 infections are limited. During March 1–May 30, 2020, as part of Vaccine Safety Datalink (VSD) surveillance of COVID-19 hospitalizations, 105 hospitalized pregnant women with SARS-CoV-2 infection were identified, including 62 (59%) hospitalized for obstetric reasons (i.e., labor and delivery or another pregnancy-related indication) and 43 (41%) hospitalized for COVID-19 illness without an obstetric reason. Overall, 50 (81%) of 62 pregnant women with SARS-CoV-2 infection who were admitted for obstetric reasons were asymptomatic. Among 43 pregnant women hospitalized for COVID-19, 13 (30%) required intensive care unit (ICU) admission, six (14%) required mechanical ventilation, and one died from COVID-19. Prepregnancy obesity was more common (44%) among pregnant women hospitalized for COVID-19 than that among asymptomatic pregnant women hospitalized for obstetric reasons (31%). Likewise, the rate of gestational diabetes (26%) among pregnant women hospitalized for COVID-19 was higher than it was among women hospitalized for obstetric reasons (8%). Preterm delivery occurred in 15% of pregnancies among 93 women who delivered, and stillbirths (fetal death at ≥20 weeks' gestation) occurred in 3%. Antenatal counseling emphasizing preventive measures (e.g., use of masks, frequent hand washing, and social distancing) might help prevent COVID-19 among pregnant women,§ especially those with prepregnancy obesity and gestational diabetes, which might reduce adverse pregnancy outcomes.

VSD is a collaboration between CDC's Immunization Safety Office and nine U.S. health care organizations serving more than 12 million persons each year. Hospitalizations with a patient diagnosis of COVID-19 were identified using COVID-19 International Classification of Diseases, Tenth Revision, Clinical Modification, (ICD-10-CM) and site-specific internal diagnosis codes during March 1–May 30, 2020. Pregnant women were identified using a validated algorithm based on ICD-9 diagnosis and procedure codes[4] that has been modified for ICD-10. For this study, medical records of women hospitalized with COVID-19 were reviewed by abstractors and adjudicated by a physician to identify the primary reason for hospital admission, pregnancy characteristics, COVID-19 complications, and birth outcomes among women who delivered before July 31, 2020.

Pregnant women with COVID-19 diagnoses were classified into the following three groups based on the primary reason for admission: 1) treatment of COVID-19 without an obstetric reason (e.g., worsening respiratory distress); 2) an obstetric reason, along with symptoms consistent with COVID-19 (e.g., fever, chills, cough, shortness of breath); and 3) an obstetric reason, without COVID-19–compatible symptoms (or with a history of resolved COVID-19), but with a positive test result for SARS-CoV-2 at the time of admission. Demographic and pregnancy characteristics among pregnant women admitted for COVID-19 were compared with those of women admitted for obstetric reasons. Birth outcomes in pregnant women with SARS-COV-2 infection were compared with background rates among all pregnant women in eight VSD sites during the study period. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.** SAS software (version 9.4; SAS Institute) was used to conduct all analyses.

During March 1–May 30, among 4,408 persons hospitalized with a COVID-19 diagnosis at VSD sites, 105 (2.4%) pregnant women were identified. SARS-CoV-2 real-time reverse transcription–polymerase chain reaction test results were positive for 104 women. One additional woman, who had a negative SARS-CoV-2 test result, was symptomatic and had close contacts with confirmed COVID-19; she received a clinical diagnosis of COVID-19. Among these 105 pregnant women, 43 (41.0%) were hospitalized for COVID-19 illness and 62 (59.0%) were admitted for obstetric reasons (Table 1). Among the 62 women admitted for obstetric reasons, 12 (19.4%) had COVID-19–compatible symptoms, and 50 (80.6%) were asymptomatic. The median age of all women was 30 years (range = 17–54 years), and 61.9% were Hispanic or Latino (Table 2). ICU admission was required for 14 (13.3%) hospitalized pregnant women, including 13 (30.2%) of the 43 women hospitalized for COVID-19; six of these women required mechanical ventilation, and one, admitted at 15 weeks' gestation, died from COVID-19. The prevalence of prepregnancy obesity (body mass index ≥30 kg/m2) was 36.2% overall and was higher among the 43 women hospitalized for COVID-19 (44.2%) than among the 62 hospitalized for obstetric reasons (30.6%). Similarly, prevalence of gestational diabetes was higher among women hospitalized for COVID-19 (25.6%) than among those hospitalized for obstetric reasons (8.1%).

Among all 105 pregnant women hospitalized with COVID-19, 93 (88.6%) had a pregnancy outcome before July 31 (Table 3), including 79 (84.9%) who delivered during their initial hospitalization and 14 (15.1%) during a subsequent hospitalization. One of the remaining 12 women died during initial hospitalization, and 11 were still pregnant at the time of analysis. Preterm delivery prevalence was 15.1% overall and 12.2% among live births, which is nearly 70% higher than baseline rates in VSD during the study period (8.9% among 43,571 live births and stillbirths in VSD). Stillbirth prevalence (3.2%) was more than four times higher among women with SARS-CoV-2 than the baseline rate in VSD during the study period (0.6%). All three stillbirths were antepartum: one with placental abruption and two with no identified etiology based on adjudication.