Synergistic effect between pre-pregnancy smoking and assisted reproductive technology on gestational diabetes mellitus in twin pregnancies.

AIM: Women with twin pregnancies have an increased risk of gestational diabetes mellitus (GDM). Assisted reproductive technology (ART) and pre-pregnancy smoking were both associated with GDM. However, the relationships between pre-pregnancy smoking and ART and GDM in twin pregnancies were unclear. Herein, this study aims to explore the roles of pre-pregnancy smoking and ART in GDM among women with twin pregnancies. METHODS: Data of women with twin pregnancies were extracted from the National Vital Statistics System (NVSS) database in 2016-2020 in this retrospective cohort study. Univariate and multivariate logistic regression analyses were used to explore the associations between pre-pregnancy smoking and ART and GDM in women with twin pregnancies. The evaluation index was odds ratios (ORs) with 95% confidence intervals (CIs). Subgroup analysis of age and BMI was also performed. RESULTS: A total of 19,860 (9.15%) women had GDM in our study. After adjusting for covariates, we found that receiving ART was associated with high odds of GDM [OR = 1.41, 95% CI (1.34-1.48)], while pre-pregnancy smoking combined with ART was associated with higher odds of GDM [OR = 1.66, 95% CI (1.14-2.42)]. In addition, these relationships were also found in women who aged ≥ 35 years old [OR = 1.98, 95% CI (1.14-3.44)] and with BMI ≥ 25 kg/m2 [OR = 1.69, 95% CI (1.11-2.55)]. CONCLUSION: Pre-pregnancy smoking may further increase the risk of GDM from ART in women with twin pregnancies. In clinical, women who are ready to receive ART treatment are recommend to quit smoking, which may reduce the risk of GDM and prevent adverse pregnancy outcomes.