Abstract: Background The association between intrauterine infection with B19 virus and the development of congenital heart disease (CHD) are still unclear. Objective To investigate the clinical characteristics of neonates with intrauterine B19 virus infection and the association between B19 virus infection and CHD. Design Retrospective cohort study. Methods Neonates who were hospitalized in the Children's Hospital of Fudan University from September 2017 to April 2023 and underwent serum B19 virus IgM testing within 21 d after birth were included. B19 virus IgM-positive cases detected at 0-14 d postnatal (hereinafter referred to as: positive group within 14 d) were seperated from 0-21 d B19 virus IgM-positive cases detected at 0-21 d (hereinafter referred to as: positive group within 21 d). The control groups were randomly matched with the positive group within 21 d (control group 1) and with the positive group within 14 d (control group 2) according to gender and the same season of the birth rows 1: 3. Clinical information including B19 virus infection and CHD were collected from the medical record system. Main outcome measures The association of neonatal positive B19 virus IgM and CHD. Results There were 83 cases in the positive group within 21 d, including 18 cases of CHD, 30 cases in the positive group within 14 d, including 9 cases of CHD, 249 cases in the control group 1, including 31 cases of CHD, and 112 cases in the control group 2, including 16 cases of CHD. The proportions of CHD, combined thoracic/abdominal/other cavity effusion , decreased Hb with no increase in Ret, decreased albumin, increased ALT were higher in the positive group within 21 d than in the control group, and the differences were statistically significant. Except for ALT, the results of the positive group within 14 d with the control group were the same as those of the positive group within 21 d with the control group. Multifactorial logistic regression analysis showed that both positive group within 21 d and positive group within 14 d were associated with CHD（OR21 d positive=2. 695, 95%CI: 1. 058~7. 545, P=0. 049, OR14 d positive=5. 166, 95%CI: 1. 034~25. 814, P=0. 045） Combined thoracic/abdominal/other cavity effusion were associated with the development of CHD both in positive group within 21 d and positive group within 14 d. Conclusion There was an association between intrauterine infection with B19 virus and the development of CHD. Newborns whose B19 virus IgM positive within 0-14 d or 0-21 d after birth, signs of edema (thoracic/abdominal/other cavity effusion) further indicate the risk of CHD, and cardiovascular examinations need to be carried out in time.

Key words: Parvovirus B19, CHD, Positive IgM, Neonate