Assisted reproductive technology and birth defects: analysis of the mediating pathways in twin pregnancies

OBJECTIVE: To systematically evaluate the epidemiological association between ART and the risk of birth defects. METHODS: Based on the latest provincial monitoring data from a large sample in Hunan Province, China for the period 2023-2024, we conducted a retrospective study comparing baseline characteristics between ART-conceived and naturally-conceived pregnancies. Through multivariable logistic regression, we estimated ART-birth defect associations, with interaction analyses across key subgroups. Besides, we performed mediation analysis to quantify twin pregnancy's role in the ART-birth defect relationship. RESULTS: = 0.007) had significant interaction effects on the association between ART and birth defects. In addition, in the mediation analysis, twin pregnancies could explain 14.33% of the relative impact of ART on birth defects. CONCLUSIONS: This study has found that the use of ART increases the risk of birth defects. In the association between ART and birth defects, twin pregnancies accounted for 14.33%.