Receipt of inactivated COVID-19 vaccine had no adverse influence on embryo implantation, clinical pregnancy and miscarriage in early pregnancy.

This work was supported by the National Natural Science Foundation of China for Young Scholars (81601275, 31801251) and the National Natural Science Foundation of China (82071721).

Allotey, J., Stallings, E., Bonet, M., Yap, M., Chatterjee, S., Kew, T., Debenham, L., Llavall, A.C., Dixit, A., Zhou, D., et al. (2020). Clinical Table 1 Baseline clinical characteristics and embryo warming-transferred cycle outcomes of patients V ariable Group 1 (n=192) Control (n=451) P value (adjusted) Group 2 (n=268) Control (n=585) P value (adjusted) Female age (year) 33.20±4.74 32.56±4.20 0.159 33.95±4.47 33.69±4.03 0.615 Male age (year) 34.47±6.43 33.88±4.83 0.088 34.95±5.29 35.04±5.22 0.658 Female BMI 22.34±3.71 22.70±3.70 0.608 22.46±3.11 22.41±3.32 0.062 Male BMI 25.04±3.67 25.76±4.02 0.327 25.23±4.62 25.36±3.90 0.692 Type of infertility 0.829 0.884 Primary 129/192 (67.19) 295/451 (65.41) 145/268 (54.10) 330/585 (56.41) Secondary 63/192 (32.81) 156/451 (33.59) 123/268 (45.90) 255/585 (43.59) Duration of infertility 4.66±3.11 4.42±3.19 0.320 5.51±4.02 4.90±3.52 0.651 Etiology of infertility 0.333 0.703 Tubal 55/192 (28.65) 116/451 (25.72) 61/268 (22.76) 142/585 (24.27) Male factor 31/192 (16.15) 96/451 (21.29) 49/268 (18.28) 107/585 (18.29) Endometriosis 7/192 (3.65) 38/451 (8.43) 13/268 (4.85) 28/585 (4.79) Ovulatory disorder 45/192 (23.44) 109/451 (24.17) 62/268 (23.13) 141/585 (24.10) Uterine factor 4/451 (0.89) 4/268 (1.49) 7/585 (1.20) Unexplained infertility 9/192 (4.69) 44/451 (9.76) 11/268 (4.10) 46/585 (7.86) Others 45/192 (23.44) 44/451 (9.76) 68/268 (25.37) 114/585 (19.49) Endometrial thickness on transfer day (mm) 10.23±1.65 9.87±1.76 0.181 9.77±1.68 9.96±1.61 0.494 Number of transferred embryo 1.92±1.65 1.90±0.29 0.402 1.02±0.14 105±0.03 0.877 Implantation rate (%) 25.00 (92/368) 28.47 (244/857) 0.663 38.46 (105/273) 39.22 (242/617) 0.692 Clinical pregnancy rate (%) 39.58 (76/192) 43.43 (196/451) 0.088 38.43 (103/268) 40.00 (234/585) 0.797 Miscarriage rate (%) 6.58 (5/76) 7.65 (15/196) 0.543 13.59 (14/103) 10.68 (25/234) 0.477 Ectopic pregnancy rate (n) 2 1 NS 0 1 NS 2333Wang, Y., et al. Sci China Life Sci November (2022) Vol.65 No.11 manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis. BMJ m3320. Flynn, A.C., Kavanagh, K., Smith, A.D., Poston, L., and White, S.L. (2021). The impact of the COVID-19 pandemic on pregnancy planning behaviors. Womens Health Rep 2, 71–77. Jing, Y ., Run-Qian, L., Hao-Ran, W., Hao-Ran, C., Ya-Bin, L., Yang, G., and Fei, C. (2020). Potential influence of COVID-19/ACE2 on the female reproductive system. Mol Hum Reprod 26, 367–373. Li, X.N., Huang, Y ., Wang, W., Jing, Q.L., Zhang, C.H., Qin, P .Z., Guan, W.J., Gan, L., Li, Y .L., Liu, W.H., et al. (2021). Effectiveness of inactivated SARS-CoV-2 vaccines against the Delta variant infection in Guangzhou: a test-negative case-control real-world study. Emerg Microbes Infect 10, 1751–1759. Lu, L., Zhang, H., Zhan, M., Jiang, J., Yin, H., Dauphars, D.J., Li, S.Y ., Li, Y ., and He, Y .W. (2020). Antibody response and therapy in COVID-19 patients: what can be learned for vaccine development? Sci China Life Sci 63, 1833–1849. Orvieto, R., Segev-Zahav, A., and Aizer, A. (2021). Does COVID-19 infection influence patients’ performance during IVF-ET cycle?: an observational study. Gynecol Endocrinol 37, 895–897. Rouse, C.E., Eckert, L.O., Babarinsa, I., Fay, E., Gupta, M., Harrison, M.S., Kawai, A.T., Kharbanda, E.O., Kucuku, M., Meller, L., et al. (2017). Spontaneous abortion and ectopic pregnancy: case definition & guidelines for data collection, analysis, and presentation of maternal immunization safety data. V accine35, 6563–6574. Y ue, L., Zhou, J., Zhou, Y ., Y ang, X., Xie, T., Yang, M., Zhao, H., Zhao, Y ., Yang, T., Li, H., et al. (2021). Antibody response elicited by a third boost dose of inactivated SARS-CoV-2 vaccine can neutralize SARS- CoV-2 variants of concern. Emerg Microbes Infect 10, 2125–2127. Y ue, L., Xie, T., Yang, T., Zhou, J., Chen, H., Zhu, H., Li, H., Xiang, H., Wang, J., Yang, H., et al. (2022). A third booster dose may be necessary to mitigate neutralizing antibody fading after inoculation with two doses of an inactivated SARS-CoV-2 vaccine. J Med Virol 94, 35–38. 2334 Wang, Y., et al. Sci China Life Sci November (2022) Vol.65 No.11