Clinical and economic analysis of the 2009 H1N1 influenza pandemic among pregnant Korean women

• Main Authors: Won Suk Choi, Min Joo Choi, Ji Yoon Noh, Joon Young Song, Woo Joo Kim, Dae Won Park, Jacob Lee, Yu Bin Seo, Ji Hyeon Baek, Sooran Choi, Hee Jin Cheong
• Format: Article
• Language: English
• Published: The Korean Association of Internal Medicine 2019-09-01
• Series: The Korean Journal of Internal Medicine
• Subjects: pandemics; h1n1; influenza, human; pregnancy
• Online Access: http://www.kjim.org/upload/pdf/kjim-2017-107.pdf

Background/Aims Unlike Western countries, the 2009 pandemic influenza infection among pregnant women was reported as mild in a previous interim study in South Korea. However, several mortalities were reported thereafter, suggesting that nationwide data were lacking. Methods This case-control study covers the entire 2009 pandemic inf luenza period, from May 2009 to February 2010. The clinical and economic data of pregnant (case) and age-matched non-pregnant (control) women with influenza A (H1N1) pdm09 virus (H1N1pdm09) infection were retrospectively collected from nine hospitals in South Korea. Results A total of 130 pregnant women with H1N1pdm09 infection were identified. The mean age of the pregnant women was 31.1 years (range, 19 to 41) and mean gestational age was 18.4 weeks (range, 3 to 40). Both case and control groups were similar in terms of age (p = 0.43) and comorbidities (p = 0.18). The overall rate of complications was comparable between the two groups (p = 0.648). However, mortality was reported only among the cases, so mean economic per capita burden is estimated to be higher for pregnant women compared to the control (4,821,992 Korean won [KRW] vs. 351,233 KRW, p = 0.31). Obstetric complications were observed in 12 cases, including preterm labor (n = 7), low birth-weight (n = 3), miscarriage (n = 1), stillbirth (n = 1), and cleft lip (n = 1). Conclusions Although statistically insignificant, the detrimental impact of influenza A H1N1pdm09 on pregnancy can be serious in some complicated cases in South Korea. Thus, the strong recommendation of influenza vaccination should be maintained for pregnant women as a high priority.