Clinical characteristics of pregnant women with COVID-19 in Japan: a nationwide questionnaire survey

Abstract

Background Few reports have presented an overall view of pregnant women with coronavirus disease 2019 (COVID-19) across an entire country and throughout the entire gestation period. Furthermore, no such reports are available for Japan. We examined the clinical characteristics and outcomes of pregnant women with COVID‑19 on a national scale in Japan. Methods A nationwide questionnaire-based survey for all 2,185 maternity services in Japan was conducted between July and August 2020. Information regarding maternal characteristics and epidemiological, clinical, treatment, and perinatal outcomes of pregnant women diagnosed with COVID-19 between 16 January and 30 June 2020 were collected. Main outcome measures were incidence of pregnant women with COVID-19 and infant infection, positive rate of the universal screening test for asymptomatic pregnant women, identification of infection route and rates of maternal death, and severe cases. Results Responses from 1,418 institutions were assessed (65% of all delivery institutions in Japan). Seventy-two pregnant women were reported to have been diagnosed with COVID-19. The positive rate of the universal screening test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among asymptomatic pregnant women was 0.03% (2/7428). The most common route of infection was familial (57%). Fifty-eight pregnant women with COVID-19 were symptomatic, of whom five (8.6%) had a severe infection and one died (a tourist). Severe respiratory symptoms, oxygen administration, and pneumonia were frequently reported in the third trimester and postpartum period compared with in early pregnancy (22.2% vs 2.5% [P = 0.03], 38.9% vs 7.5% [P = 0.01], and 50.0% vs 7.5% [P < 0.001], respectively). All pregnant women with COVID-19 underwent caesarean sections, regardless of symptoms. There were no SARS-CoV-2 transmissions to newborns. Conclusions In Japan, the number of cases of COVID-19 infection in pregnant women is very low. Compared with early pregnancy, late pregnancy may be a risk factor for exacerbation of symptoms and familial transmission is the most common route of infection. The importance of infection prevention should be emphasised, especially in women in late pregnancy, their families, and any cohabitants.

Risk factors for severe disease and impact of severity on pregnant women with COVID-19: a case–control study based on data from a nationwide survey of maternity services in Japan

“…Our study examined a larger number of cases by subdividing the severity of the disease and found that severe cases were associated with late pregnancy (ie, the second half of the second trimester and later). Other reports of more cases requiring hospitalisation or severe cases in late pregnancy may support our results 7 9 11. The higher risk of severe illness in late pregnancy is similar to that of other respiratory viral infections, such as influenza 12 13.…”

“…7 8 We have already reported the clinical characteristics of infected pregnant women from January 2020, when the first cases of COVID-19 were reported in Japan, to June 2020, when the first wave of infection ended, showing that late pregnancy may be a risk factor for exacerbation of symptoms, and familial transmission is the most common route of infection. 9 The number of cases, including severe cases, was small, and further accumulation of cases and examination of the impact of infection on perinatal outcomes was the next issue. We investigated the risk factors of severe COVID-19 in pregnant women and the effect of severe cases on preterm birth based on the results of a nationwide questionnaire survey in Japan.…”

Threatened abortion, threatened premature labor, and preterm birth during the first state of emergency for COVID‐19 in 2020 in Japan

“…From January to June 2020, an estimated 0.03% of pregnant women were confirmed to have COVID‐19 in 1418 facilities across the country. 25 Furthermore, a study reported that the number of neonatal intensive care unit admissions, neonatal resuscitation, and preterm birth decreased during the COVID‐19 outbreak, based on the administrative data of 186 hospitals. 26 To further assess this evidence, we examined the incidence of threatened abortion, threatened premature labor, and preterm birth before, during, and after the first state of emergency for COVID‐19 in 2020 in Japan, based on maternal reports.…”

Vaginal delivery after improvement in COVID-19 by monoclonal antibody treatment: A case report and literature review

“…Of these patients, 3 had a gestational age of 30 weeks or more; 2 cases (including this one) resulted in delivery during the treatment period against COVID-19. We performed a literature review of perinatal cases of COVID-19 in Japan [ [11] , [12] , [13] ], along with the first report of a 37-week pregnant woman with COVID-19 pneumonia who delivered a male newborn through a cesarean section in 2020 [ 14 ] ( Table 1 ). We searched for related articles by entering keywords ‘‘casirivimab, imdevimab, pregnant’’ into the PubMed database ( https://pubmed.ncbi.nlm.nih.gov/ ), and only one report described 2 cases of childbirth after treatment with C&I from the US in December 2021 [ 15 ].…”