Background: Reluctance of people to receive recommended vaccines is a growing concern as 2 distribution of vaccines is considered critical to ending the COVID-19 pandemic. There is little 3 information regarding pregnant women's views toward coronavirus vaccination in Japan.4 Therefore, we investigated the vaccination rate and reasons for vaccination and vaccine 5 hesitancy among pregnant women in Japan.6 Methods: We conducted a cross-sectional study involving 1,791 pregnant women using data 7 from the Japan "COVID-19 and Society" Internet Survey, conducted from July to August 2021, 8 and valid response from 1,621 respondents were analyzed. We defined participants with 9 vaccine hesitancy as those who identified with the statement "I do not want to be vaccinated" or "I want to 'wait and see' before getting vaccinated." Multivariate Poisson regression analysis was used to investigate the factors contributing to vaccine hesitancy. Results:The prevalence of vaccination and vaccine hesitancy among pregnant women was 13.4% (n=217) and 50.9% (n=825), respectively. The main reasons for hesitancy were concerns about adverse reactions and negative effects on the fetus and breastfeeding. The significant factor for vaccine hesitancy was the lack of trust in the government (adjusted PR, 1.26; 95% CI, 1.03-1.54). Other factors such as age, educational attainment, state of emergency declaration were not associated with vaccine hesitancy.Conclusions: COVID-19 vaccination is not widespread among pregnant women in Japan although many vaccines have been shown to be safe in pregnancy. Accurate information dissemination and boosting trust in the government may be important to address vaccine hesitancy among pregnant women.

Aim: Postoperative pulmonary embolism can be a fatal surgical complication and is thought to occur secondary to asymptomatic venous thromboembolism (VTE) that exists preoperatively in some patients. The purpose of this study was to clarify the frequency and risk factors of pretreatment VTE in gynecological cancer patients. Methods: This study investigated 2086 patients with gynecological cancer (cervix, n = 754; endometrium, n = 862; ovary, n = 470) who underwent initial treatment between 2004 and 2017. Pretreatment VTE screening was performed with D-dimer (DD) levels in these patients. Based on this, the associated risk factors were retrospectively analyzed. Results: Pretreatment VTE was discovered in 7.3% of patients with cervical cancer, 11.5% of those with endometrial cancer and 27.0% of those with ovarian cancer. Significant independent risk factors were: age greater than or equal to 60 years and tumor long diameter greater than or equal to 40 mm for cervical cancer; age greater than or equal to 60 years, stage III/IV advanced disease, clear cell carcinoma and tumor long diameter greater than or equal to 60 mm for endometrial cancer; and age greater than or equal to 60 years, clear cell carcinoma and massive ascites for ovarian cancer. Conclusion: Pretreatment asymptomatic VTE is very frequent in gynecological cancer patients. It may be beneficial to consider measuring DD or performing venous ultrasonography in patients with the above risk factors.

ObjectivesOur 2007 study of 32 patients with ovarian cancer reported the possible involvement of tissue factor (TF) in the development of venous thromboembolism (VTE) before treatment, especially in clear cell carcinoma (CCC). This follow-up study further investigated this possibility in a larger cohort.MethodsWe investigated the intensity of TF expression (ITFE) and other variables for associations with VTE using univariate and multivariate analyses in 128 patients with epithelial ovarian cancer initially treated between November 2004 and December 2010, none of whom had received neoadjuvant chemotherapy. Before starting treatment, all patients were ultrasonographically screened for VTE. The ITFE was graded based on immunostaining of surgical specimens.ResultsHistological types were serous carcinoma (n = 42), CCC (n = 12), endometrioid carcinoma (n = 15), mucinous carcinoma (n = 53), and undifferentiated carcinoma (n = 6). The prevalence of VTE was significantly higher in CCC (34%) than in non-CCC (17%, P = 0.03). As ITFE increased, the frequencies of CCC and VTE increased significantly (P < 0.001 and P = 0.014, respectively). Multivariate analysis identified TF expression and pretreatment dimerized plasmin fragment D level as significant independent risk factors for VTE development. These factors showed particularly strong impacts on advanced-stage disease (P = 0.021).ConclusionsThe 2007 cohort was small, preventing multivariate analysis. This study of a larger cohort yielded stronger evidence that the development of VTE in epithelial ovarian cancer may involve TF expression in cancer tissues.

ObjectivesKnowledge on the impact of heated tobacco product (HTP) use in pregnant women with associated maternal and neonatal risks for hypertensive disorders of pregnancy (HDP) and low birth weight (LBW) is limited. We aimed to assess the status of HTP use among pregnant women in Japan and explore the association of HTP use with HDP and LBW.DesignCross-sectional study.SettingData from the Japan ‘COVID-19 and Society’ Internet Survey study, a web-based nationwide survey.ParticipantsWe investigated 558 postdelivery and 365 currently pregnant women in October 2020.Primary and secondary outcome measuresInformation on HDP and LBW was collected from the postdelivery women’s Maternal and Child Health Handbooks (maternal and newborn records). We estimated the age-adjusted ORs and 95% CIs of ever HTP smokers for HDP and LBW and compared them with those of never HTP smokers in a logistic regression analysis.ResultsThe prevalence of ever and current HTP use were 11.7% and 2.7% in postdelivery women and 12.6% and 1.1% in currently pregnant women, respectively. Among currently pregnant women who were former combustible cigarette smokers, 4.4% (4/91) were current HTP smokers. Among postdelivery women, ever HTP smokers had a higher HDP incidence (13.8% vs 6.5%, p=0.03; age-adjusted OR=2.48, 95% CI 1.11 to 5.53) and higher LBW incidence (18.5% vs 8.9%, p=0.02; age-adjusted OR=2.36, 95% CI 1.16 to 4.87).ConclusionsIn Japan, the incidence of ever HTP use exceeded 10% among pregnant women, and HTP smoking may be associated with maternal and neonatal risks.