key: cord-0837407-9jm5i1y1 authors: Gabrieli, Dana; Cahen‐Peretz, Adva; Shimonovitz, Tzvika; Marks‐Garber, Keren; Amsalem, Hagai; Kalish, Yosef; Lavy, Yuval; Walfisch, Asnat title: Thromboembolic events in pregnant and puerperal women after COVID‐19 lockdowns: A retrospective cohort study date: 2021-07-29 journal: Int J Gynaecol Obstet DOI: 10.1002/ijgo.13777 sha: b1ade832c4430fb234f37344c3a4783f8b272ece doc_id: 837407 cord_uid: 9jm5i1y1 OBJECTIVE: To explore the indirect impact of the COVID‐19 pandemic on patterns of pregnancy‐related venous thromboembolism (VTE) events, mediated by population mobility restrictions during lockdown periods. METHODS: Pregnancy‐related VTE hospitalizations were identified through a code‐targeted search of the Hadassah Medical Center's computerized database. A manual analysis of relevant medical records was performed, and cases diagnosed throughout the year 2020 were compared to those diagnosed during 2019 and 2018. Statistical analyses studied obstetrical outcomes, as well as the extent and treatment of VTE events during the COVID‐19 pandemic compared to those of preceding years, stratified by pre‐, intra‐, and post‐lockdown periods. RESULTS: The incidence of pregnancy‐related thromboembolic events during 2020 was 0.16% of all deliveries, significantly higher than in 2018 and 2019 (0.06% and 0.1%, respectively; P < 0.05). Higher rates of VTE events were found during post‐lockdown periods in 2020, compared with corresponding time periods in 2019 and 2018. CONCLUSION: The present data suggest that lockdown periods impact pregnancy‐related VTE hospitalizations, possibly as a result of restricted population mobility. Increased awareness of this undesirable outcome may aid health policymakers in the continuing struggle with epidemics. The risk of VTE events increases as the pregnancy progresses, peaking in the postpartum period. Approximately 80% of pregnancyassociated VTE events are DVTs, half of which occur during the postpartum period. When occurring during pregnancy, under the influence of estrogen, DVT is more likely to be proximal, massive, and in the left extremity. 2 The causes for VTE are presented in Virchow's triad: hypercoagulability; vascular damage; and venous stasis. Pregnancy is a state characterized by all three conditions, thereby increasing the risk of VTE events among pregnant and postpartum women. 4 Hypercoagulability is the main reason for the increased risk of thromboembolism during pregnancy, as pregnancy is, by definition, a hypercoagulable state. Normal hemodynamic changes occurring during pregnancy include increased levels of clotting factors, decreased levels of natural anticoagulants, and diminished fibrinolytic activity. These changes facilitate normal placental function during pregnancy and prevent excessive bleeding during delivery, yet at the same time predispose to thrombosis. 5 Venous stasis in pregnancy results from dilation of the lower extremity veins, followed by venous compression by the gravid uterus and enlarging iliac arteries. Circumstances characterized by limited mobility (such as surgery, cesarean delivery, bed rest, or air travel) may further elevate this risk. 6 Findings from the RIETE registry, in which more than 10 000 women who presented with acute VTE had been enrolled, concluded that one in every four pregnant women developed VTE shortly after surgery or prolonged immobility. 1 Although numerous publications studied the direct COVID-19-associated coagulopathy, 7 the present study focused on the less-studied potential indirect effect of the pandemic on pregnancyrelated VTE morbidity. Many countries have taken measures to limit personal mobility in order to prevent the spreading of COVID-19. Yet, it is believed that no study has explored the impact of immobilization during lockdown periods on pregnancy-related VTE events. The aim of the present study was to determine whether the COVID-19 pandemic is associated with a higher incidence of pregnancy-related VTE events, unrelated to COVID-19 infection. It was hypothesized that a pattern may be suggested, associated with lockdown periods. Comparison of the cases of pregnancy-related VTE was performed on the annual level (to estimate the overall differences in pregnancy-related VTE hospitalizations, as well as demographic, obstetrical, and therapeutic characteristics). Hospitalizations during 2020 were compared to the 2 preceding years. The incidence of VTE was also compared by calendar month in order to limit the effect of seasonality and further characterize the impact of national lockdowns on the incidence of VTE. Statistical analyses were performed in Python 3.7.6, using the Pandas 1.0.1 and SciPy 1.4.1 libraries. Quantitative variables were compared by the Kruskal-Wallis test. Categorical variables were compared using the χ 2 test. Statistical significance was set at Review Board in accordance with the Helsinki declaration. In an attempt to visualize the possible effects of lockdowns on the incidence of VTE incidence, the calendar year was subdivided into three time periods, according to the mobility restrictions that were enforced during 2020 in Israel: January and February were considered pre-lockdown periods; March, April, and September were considered lockdown periods; and May to August and October to December were considered post-lockdown periods. As shown in The year 2020 was characterized by a higher incidence of pregnancy-related VTE events necessitating hospitalizations compared to previous years. This higher rate was evident specifically during the two post-lockdown periods, suggesting a lag effect On the other hand, the small number of cases of pregnancyrelated VTE has limited the ability to identify small but significant differences in severity and therapeutic option characteristics among relevant cases over the studied years. Another limitation to note is that women diagnosed recently (i.e. in 2020) have not yet completed their hypercoagulability investigation, while older cases have (2018-2019). Furthermore, being a retrospective medical file-based study, the lack of information due to incomplete documentation made it difficult to perform an accurate analysis of demographic characteristics (for instance, missing data regarding body mass index). To conclude, the COVID-19 pandemic appears to bear indirect effects that spread beyond the immediate and intuitive ones. National lockdowns may result in health implications for the public in general and specifically for pregnant women. The present study suggests an association between national lockdowns resulting in relative immobilization and an increase in the incidence of pregnancy-related VTE events. As VTE in pregnant women can be a life-threatening event, it is felt that the findings of the present study should be incorporated into continued health-policy recommendations. Maintaining an active lifestyle, especially during pregnancy and regardless of national lockdowns, may prove to have a paramount impact on maternal health. The importance of avoiding immobility in times of either lockdown or quarantine should be stressed and translated into practical assistance. The authors have no conflicts of interest. ACP and DB contributed equally. Both authors planned the study, performed manual data collection and data analysis, wrote and edited the manuscript. AW conceived the original idea of the study and was in charge of overall direction and planning, discussed, commented, edited and finally approved the manuscript. HA was involved in planning the design of the study, supervised the work, discussed, commented, edited and finally approved the manuscript. KM participated in data collection, discussed, commented, edited and finally approved the manuscript. TS participated in the manual data collection, planning the design of the study, supervised the work, discussed, commented, edited and finally approved the manuscript. YK was involved in planning the design of the study, supervised the work, discussed, commented, edited and finally approved the manuscript. YL was involved in planning the design of the study, supervised the work, discussed, commented, edited and finally approved the manuscript. Association of specific haplotypes of GAS6 gene with stroke Pregnancy-associated thrombosis Risk factors for venous thromboembolism in 1.3 million pregnancies: a nationwide prospective cohort Venous thromboembolism during pregnancy Haemostatic changes in pregnancy Venous thromboembolic disease and pregnancy COVID-19 coagulopathy in pregnancy: Critical review, preliminary recommendations, and ISTH registry-Communication from the ISTH SSC for Women's Health The New Hadassah-Hebrew University Medical Center: a leader in Israeli Public Medicine Pregnancy and COVID-19 COVID-19 (SARS-CoV-2) infection in pregnancy: a systematic review The impact of the COVID-19 pandemic on hospital admissions in the United States COVID-19 pandemic and admission rates for and management of acute coronary syndromes in England Reduction of hospitalizations for myocardial infarction in Italy in the COVID-19 era Decrease in infection-related hospital admissions during COVID-19: why are parents avoiding the doctor? How to cite this article: Gabrieli D, Cahen-Peretz A Thromboembolic events in pregnant and puerperal women after COVID-19 lockdowns: A retrospective cohort study