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. 2022 Jan 17:ciac028. doi: 10.1093/cid/ciac028

Clinical characteristics and outcomes of COVID-19 in pregnant women: a propensity score matched analysis of the data from the COVID-19 Registry Japan

Kensuke Shoji 1,, Shinya Tsuzuki 2, Takayuki Akiyama 3, Nobuaki Matsunaga 4, Yusuke Asai 5, Setsuko Suzuki 6, Noriko Iwamoto 7, Takanori Funaki 8, Masaki Yamada 9,10, Nobuaki Ozawa 11, Koushi Yamaguchi 12, Isao Miyairi 13,14, Norio Ohmagari 15,16
PMCID: PMC8807242  PMID: 35037051

Abstract

Background

Several studies have investigated whether pregnancy is a risk factor for developing severe COVID-19; however, the results remain controversial. In addition, the information regarding risk factors for developing severe COVID-19 in pregnant women is limited.

Methods

A retrospective cohort study analyzing the data from the nationwide COVID-19 registry in Japan was conducted. Propensity score matched analysis was performed to compare COVID-19 severity between pregnant and nonpregnant women. Multivariate analysis was also conducted to evaluate risk factors for developing moderate-to-severe COVID-19 in pregnant women.

Results

During the study period, 254 pregnant and 3752 nonpregnant women of reproductive age were identified. After propensity score matching, 187 pregnant women and 935 nonpregnant women were selected. A composite outcome of moderate-to-severe COVID-19 was more frequently observed in pregnant women than that of nonpregnant women (n=18, 9.6% vs. n=46, 4.9%; P=0.0155). In multivariate analysis, the presence of underlying diseases and being in the second-to-third trimester of pregnancy were recognized as risk factors for moderate-to-severe COVID-19 in pregnant women (odds ratio [95% confidence interval]: 5.295 [1.21-23.069] and 3.871 [1.201-12.477], respectively).

Conclusions

Pregnancy could be a risk factor for moderate-to-severe COVID-19 for women in Japan. In addition to the presence of comorbidities, advanced pregnancy stages may contribute to greater risks for developing moderate-to-severe COVID-19 in pregnant women.

Keywords: pregnant women, coronavirus disease 2019, severe acute respiratory syndrome coronavirus 2, propensity score matched analysis

Contributor Information

Kensuke Shoji, Division of Infectious Diseases, Department of Medical Subspecialties, National Center for Child Health and Development, Tokyo, Japan.

Shinya Tsuzuki, AMR Clinical Reference Center, National Center for Global Health and Medicine, Tokyo, Japan.

Takayuki Akiyama, AMR Clinical Reference Center, National Center for Global Health and Medicine, Tokyo, Japan.

Nobuaki Matsunaga, AMR Clinical Reference Center, National Center for Global Health and Medicine, Tokyo, Japan.

Yusuke Asai, AMR Clinical Reference Center, National Center for Global Health and Medicine, Tokyo, Japan.

Setsuko Suzuki, Department of Infectious Diseases, Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan.

Noriko Iwamoto, Department of Infectious Diseases, Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan.

Takanori Funaki, Division of Infectious Diseases, Department of Medical Subspecialties, National Center for Child Health and Development, Tokyo, Japan.

Masaki Yamada, Division of Infectious Diseases, Department of Medical Subspecialties, National Center for Child Health and Development, Tokyo, Japan; Department for Advanced Medicine for Viral Infections, National Center for Child Health and Development, Setagaya-ku, Tokyo, Japan.

Nobuaki Ozawa, Center for Maternal-Fetal, Neonatal and Reproductive Medicine, National Center for Child Health and Development, Tokyo, Japan.

Koushi Yamaguchi, Center for Maternal-Fetal, Neonatal and Reproductive Medicine, National Center for Child Health and Development, Tokyo, Japan.

Isao Miyairi, Division of Infectious Diseases, Department of Medical Subspecialties, National Center for Child Health and Development, Tokyo, Japan; Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan.

Norio Ohmagari, AMR Clinical Reference Center, National Center for Global Health and Medicine, Tokyo, Japan; Department of Infectious Diseases, Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan.

Supplementary Material

ciac028_suppl_Supplementary_Tables

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

ciac028_suppl_Supplementary_Tables

Articles from Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America are provided here courtesy of Oxford University Press

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