Purpose: The aim of the present study was to quantify the rate of thromboembolic events (TE) in pregnant women with SARS-CoV-2 infection and to characterize risk factors to provide a basis for individualized recommendation on prophylactic measures. Methods: CRONOS is a multicenter, prospective observational study conducted in Germany and Austria during the COVID-19 pandemic. Pregnant women with confirmed SARS-CoV-2 infection were enrolled. Data on demographics, medical history, COVID-19-related aspects, and pregnancy and birth outcomes were collected. TE was particularly queried and used as the primary outcome. A combination of “TE,” “maternal or fetal death,” or “severe postpartum hemorrhage” was defined as a secondary endpoint. Risk analyses were performed using univariate and multivariable logistic regression models. Results: Data from 8033 pregnant patients showed 40 TEs (0.5% incidence). TE rates were 10% in ICU patients, 0.2–0.4% in those with moderate-to-mild COVID-19, and < 0.1% in asymptomatic women. Pulmonary embolism occurred in 21 cases, deep vein thrombosis in 12, and 7 had atypical or arterial TE. Risk factors included advanced gestational age, COVID-19 symptoms, hospitalization or ICU admission, premature birth, cesarean section, delivery within 4 weeks of infection, higher weight gain, anemia, and chronic inflammatory bowel disease. COVID-19 vaccination reduced risk. The logistic risk model yielded an AUC of 0.87 (95% CI 0.81–0.94). Conclusion: The TE rate in pregnant women is largely determined by the severity of the disease. In asymptomatic or mild cases, other factors outweigh TE risk, while severe COVID-19 requiring ICU admission poses a high TE risk despite prophylaxis.

Schwangere gehören nicht zu den typischen Patientinnen der Intensivstationen. Mit durchschnittlich zwischen 2–4 Aufnahmen pro 1000 Geburten [1] ist die Inzidenz in Europa und den USA hierfür auch entsprechend gering. Nicht nur aufgrund der Seltenheit oder der Besonderheiten einer Schwangerschaft sollte die Behandlung von schwangeren Patientinnen auf der Intensivstation immer eine interdisziplinäre und multiprofessionelle Aufgabe sein. Although admission to an intensive care unit during pregnancy is rare, pregnant women may become critically ill due to either obstetric or non-obstetric illness. Whilst critical illness due to obstetric reasons during the peripartum period (e.g. peripartum haemorrhage, HELLP-syndrome) is more common, it is also important to know how to care for critically ill pregnant women with non-obstetric illness (e.g. infection, cardiovascular diseases, neurological diseases, trauma). Physiological changes during pregnancy may affect critical care treatment, variation in standard and target values for blood pressure management or artificial ventilation. Pregnancy specific reference values in interpretation of blood chemistry are important issues to consider. The use of different drugs is inevitable in critical care, knowing which drugs are safe to use during the different stages of pregnancy is essential. Caring for mother and unborn child in the ICU is a challenge, open communication, ethical considerations and interdisciplinary as well as multiprofessional collaborations should be key points when caring for critically ill pregnant patients. Article published online: 13 October 2023 © 2023. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Almost 25 years ago, trastuzumab, a monoclonal antibody targeting the human epidermal growth factor receptor 2 (HER2), was licensed for the treatment of patients with metastatic HER2-positive breast cancer in the United States of America (USA)