Adoption of a National Prophylactic Anticoagulation Guideline for Hospitalized Pregnant Women with COVID-19: Retrospective Cohort Study.

Document Type


Publication Date


Publication Title

JMIR Public Health Surveill


washington; swedish; isb; covid-19


BACKGROUND: Both COVID-19 and pregnancy are associated with hypercoagulability. Due to increased risk for thrombosis, the United States National Institute of Health's recommendation for prophylactic anticoagulant use for pregnant patients has expanded from patients hospitalized for severe COVID-19 manifestation to all patients hospitalized for the manifestation of COVID-19 (no guideline: ~12-26-2020, first update: 12-27-2020~02-23-2022, second update: 02-24-2022~present). However, no study has evaluated this recommendation.

OBJECTIVE: The objective of this study was to characterize prophylactic anticoagulant use among hospitalized pregnant people with COVID-19 from 03-20-2020~10-19-2022.

METHODS: This was a retrospective cohort study in large US healthcare systems across seven states. The cohort of interest was pregnant patients who were hospitalized with COVID-19, without prior coagulopathy or contraindication to anticoagulants (n=2,767). The treatment group consisted of patients prescribed prophylactic dose anticoagulation during -2~+14 days from COVID-19 treatment onset (n=191). The control group was patients with no anticoagulant exposure during -14~+60 days of the SARS-CoV-2 infection date (n=2,534). We ascertained the use of prophylactic anticoagulants with attention to the updates in guidelines and emerging SARS-CoV-2 variants. We propensity score matched the treatment and control group 1:1 on the most important features contributing to the prophylactic anticoagulant administration status classification. Outcome measures included coagulopathy, bleeding, COVID-19-related complications, and maternal-fetal health outcomes. Additionally, the inpatient anticoagulant administration rate was validated in a nationwide population from Truveta, a collective of 700 hospitals across the United States.

RESULTS: The overall administration rate of prophylactic anticoagulants was 7.0% (191/2,725). It was lowest after the second guideline update (no guideline: 10.4%, first update: 9.0%, second update: 2.5%; P

CONCLUSIONS: Most hospitalized pregnant COVID-19 patients did not receive prophylactic anticoagulants across healthcare systems as recommended by guidelines. Guideline recommended treatment was administered more frequently to patients with greater COVID-19 illness severity. Given the low rate of administration and differences between treated and untreated cohorts, efficacy could not be assessed.

Clinical Institute

Women & Children


Obstetrics & Gynecology


Infectious Diseases


Institute for Systems Biology