The impact of HBV, HCV, or syphilis infections on embryo and pregnancy outcomes in couples undergoing IVF treatment: a matched cohort study.

study questionDo infectious diseases (hepatitis B virus [HBV], hepatitis C virus [HCV], and syphilis) impact embryo quality, pregnancy, and neonatal outcomes following a complete IVF cycle? SUMMARY ANSWER: Infections with HBV, HCV, or syphilis do not have detrimental impacts on live birth rates or neonatal outcomes in couples following a complete IVF cycle. WHAT IS KNOWN ALREADY: Maternal or paternal infections with HBV, HCV, or syphilis may decrease the clinical pregnancy rate, result in poorer embryo outcomes, and lower offspring birth weight. However, there is significant controversy regarding these effects across existing studies, highlighting the need for further research. STUDY DESIGN SIZE DURATION: This is a retrospective matched cohort study. Data were obtained from the clinical database of couples who underwent IVF treatment at a single academically affiliated fertility clinic from January 2011 to December 2019, with follow-up extending to December 2020. Out of 180 666 complete cycles recorded, 2443 cycles fulfilled our inclusion criteria. PARTICIPANTS/MATERIALS SETTING

methodsIn cycles that fulfilled our inclusion criteria, there were 1997 cycles in the HBV study group, 154 cycles in the HCV study group, and 292 cycles in the syphilis study group. Each study cycle was paired with four controls based on participant age and the timing of IVF treatment, resulting in 7988 controls for the HBV group, 616 controls for the HCV group, and 1169 controls for the syphilis group. Infections could be either single-parent or biparental. The primary outcome was live birth per complete cycle (i.e. fresh cycle plus subsequent frozen-thawed cycles). Subgroup analyses were conducted dividing cycles into maternal infection and paternal infection. MAIN RESULTS AND THE ROLE OF CHANCE: In the HBV group, pregnancy outcomes (clinical pregnancy, miscarriage, and live birth rates) and neonatal birth weight were similar to that of the controls. In the HCV group, no significant differences from the controls were observed except for a lower clinical pregnancy rate in the study group (36.4% vs 42.2%, adjusted β and 95% CI: 0.62 [0.39-0.96]). Similarly, no significant differences were found in pregnancy or neonatal outcomes between the syphilis group and the control group. As for subgroup analyses, the male-only HBV infection subgroup showed a higher miscarriage rate in the study group than in the control group (22.5% vs 17.7%, adjusted β and 95% CI: 1.56 [1.07-2.28]). For the HCV and syphilis subgroups, none of the outcomes showed significant differences between either the female-only infection or male-only infection subgroups and the controls. LIMITATIONS REASONS FOR CAUTION: Although potential confounders were considered and adjusted for, residual bias may still exist due to the study design. The inclusion of participants solely from a single center limited the generalizability of our findings to a broader context. WIDER IMPLICATIONS OF THE

findingsWe presented a comprehensive overview of the impact of prevalent infectious diseases on IVF outcomes, hoping to address uncertainties surrounding the decisions of couples infected with these diseases and to assist in preventing adverse reproductive outcomes in clinical practice. STUDY FUNDING/COMPETING INTERESTS: This study was supported by the National Natural Science Foundation of China (82204052), the National Key R&D Program of China (2022YFC2705305), and the Clinical key project of Peking University Third Hospital (BYSYZD2023007). The authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.