Laboratory-Confirmed Influenza Hospitalizations During Pregnancy or the Early Postpartum Period — Suzhou City, Jiangsu Province, China, 2018–2023

Pregnancy is associated with increased risk for severe illness and complications associated with influenza infection. Insufficient knowledge about the risk for influenza among pregnant women and their health care providers in China is an important barrier to increasing influenza vaccination coverage and treating influenza and its complications among pregnant women. Improved influenza incidence estimates might promote wider vaccine acceptance and higher vaccination coverage. In Suzhou, active population-based surveillance during October 2018-September 2023 estimated that the annual rate of hospitalization for acute respiratory or febrile illness (ARFI) among women who were pregnant or <2 weeks postpartum was 11.1 per 1,000 live births; the annual rate of laboratory-confirmed influenza-associated ARFI (influenza ARFI) hospitalization in this group was 2.1 per 1,000 live births. A majority of hospitalized pregnant or early postpartum patients with ARFI (82.6%; 2,588 of 3,133) or influenza ARFI (85.5%; 423 of 495) were admitted to obstetrics wards rather than respiratory medicine wards. Only one (0.03%) pregnant or postpartum ARFI patient had received influenza vaccination, and 31.3% of pregnant or postpartum women hospitalized for influenza ARFI received antiviral treatment; the lowest percentage of hospitalized women with influenza ARFI who received antiviral treatment was among women admitted to obstetrics and gynecology wards (29.6% and 23.1%, respectively), compared with 54.1% of those admitted to a respiratory medicine ward. These findings highlight the risk for influenza and its associated complications among pregnant and postpartum women, the low rates of influenza vaccination among pregnant women, and of antiviral treatment of women with ARFI admitted to obstetrics and gynecology wards. Increasing awareness of the prevalence of influenza ARFI among pregnant women, the use of empiric antiviral treatment for ARFI, and the infection control in obstetrics wards during influenza seasons might help reduce influenza-associated morbidity among pregnant and postpartum women.