Severity of illness and mortality increases in pregnant women with COVID-19: AJOG study

Population based studies of COVID-19 in pregnancy with comprehensive data regarding race, ethnicity, and language are essential to developing effective interventions for populations disproportionately affected by COVID-19.

Lokken EM, Taylor GG, Huebner EM, et al aimed to estimate and compare the infection rates between pregnant patients and similarly aged adults in Washington State and to examine the disparities by race and ethnicity and language use.

Pregnant patients with a polymerase chain reaction confirmed severe acute respiratory syndrome coronavirus 2 infection diagnosed between March 1, 2020, and June 30, 2020 were identified within 35 hospitals and clinics, capturing 61% of annual deliveries in Washington State. Infection rates in pregnancy were estimated overall and by Washington State Accountable Community of Health region and cross-sectionally compared with severe acute respiratory syndrome coronavirus 2 infection rates in similarly aged adults in Washington State. Race and ethnicity and language used for medical care of pregnant patients were compared with recent data from Washington State.

A total of 240 pregnant patients with severe acute respiratory syndrome coronavirus 2 infections were identified during the study period with 70.7% from minority racial and ethnic groups.

38 (15.8%) were detected in the first trimester of pregnancy, 67 (27.9%) in the second trimester of pregnancy, and 135 (56.3%) in the third trimester trimester of pregnancy.

The principal findings in this study were:

(1) the severe acute respiratory syndrome coronavirus 2 infection rate was 13.9 per 1000 deliveries in pregnant patients (95% confidence interval) compared with 7.3 per 1000 (95% confidence interval) in adults aged 20 to 39 years in Washington State (rate ratio, 1.7; 95% confidence interval);

(2) the severe acute respiratory syndrome coronavirus 2 infection rate reduced to 11.3 per 1000 deliveries (95% confidence interval) when excluding 45 cases of severe acute respiratory syndrome coronavirus disease 2 detected through asymptomatic screening (rate ratio, 1.3; 95% confidence interval);

(3) the proportion of pregnant patients in non-White racial and ethnic groups with severe acute respiratory syndrome coronavirus disease 2 infection was 2- to 4-fold higher than the race and ethnicity distribution of women in Washington State who delivered live births in 2018; and

(4) the proportion of pregnant patients with severe acute respiratory syndrome coronavirus 2 infection receiving medical care in a non-English language was higher than estimates of pregnant patients receiving care with limited English proficiency in Washington State (30.4% vs 7.6%).

In the early months of the COVID-19 pandemic, the SARS-CoV-2 infection rate was 70% higher in pregnant patients than in similarly aged adults in Washington State.

The infection rate remained 30% higher after excluding pregnant patients whose SARSCoV-2 infections were detected through asymptomatic screening strategies, including preprocedure and universal screening at delivery. In addition, researchers detected significant disparities in the proportion of pregnant women from racial and ethnic minority groups with SARS-CoV-2 infection, particularly among Hispanic and American Indian or Alaska Native pregnant patients; furthermore, a disproportionate number of pregnant women with SARS-CoV-2 infection received medical care in a non English language. The higher infection rates in pregnant patients coupled with an elevated risk of severe illness and maternal mortality because of COVID-19 suggests that pregnancy should be considered a high-risk health condition for COVID-19 vaccine allocation.

Although pregnancy is not considered an immunosuppressed condition, it is associated with an increased risk of disease severity for some infections and potentially, acquisition risk. Although the increased infection rate in pregnant patients may be largely driven by increased testing, the infection rate of pregnant patients remained elevated compared with the infection rate of the general population in the sensitivity analysis, excluding cases detected through universal testing preprocedure and at delivery admission.

Whether an increased infection rate in pregnancy has a biologic basis or is because of other factors, such as increased testing, greater exposure by living in intergenerational households, working in high-risk occupations (ie, healthcare, teaching, service industries), or selection bias, is unknown

The data demonstrated a disproportionate burden of SARS-CoV-2 among non-White pregnant patients in this study population in Washington State. Compared with the distribution of women in Washington State who delivered live births in 2018, the proportion of pregnant women from racial and ethnic minority groups with SARS-CoV2 infection was 2- to 4-fold higher, with the greatest disparity among Hispanic and American Indian or Alaska Native pregnant patients.

A fundamental cause of health disparities is the socioeconomic inequality that arises from structural racism and decades of limited access to quality healthcare, education, and housing. Pregnant patients with SARS-CoV-2 infection were also more likely to receive care in a non-English language compared with the statewide prevalence of patients with limited English proficiency receiving care.

The authors concluded, "During the early months of the COVID19 pandemic, pregnant patients in Washington State had a 70% higher SARS-CoV-2 infection rate than similarly aged adults, which in part reflects a population that was prioritized for testing. However, we can conclude that pregnant patients were not protected in the early months of the pandemic in Washington State by the public health response or through frequent interactions with obstetrical care providers. Furthermore, the greatest burden of infections occurred within racial and ethnic minority groups and patients preferring to receive care in a non-English language. Understanding the geographic, racial and ethnic, and language distributions of SARS-CoV-2 infections among pregnant patients would enable targeting the public health response to pregnant patients at the greatest risk of SARS-CoV-2 infection and associated adverse maternal-fetal outcomes. Broader recognition that pregnancy is a risk factor for severe illness and maternal mortality coupled with a higher infection rate in pregnancy strongly suggested that pregnant people should be broadly prioritized for COVID-19 vaccine allocation in the United States similar to some states."

Source: Lokken EM, Taylor GG, Huebner EM, et al. Higher severe acute respiratory syndrome coronavirus 2 infection rate in pregnant patients. Am J Obstet Gynecol 2021;225:75.e1-16.

https://doi.org/10.1016/j.ajog.2021.02.011