To evaluate the rates of adverse perinatal outcomes among women who conceived after fertility treatments with and without diet-controlled GDM. In this retrospective population-based cohort study, all pregnancies of non-diabetic and diet-controlled GDM women who conceived after fertility treatments (in-vitro fertilization - IVF and ovulation induction - OI) and delivered between the years 1996-2016 in a tertiary medical center, were included. Pregnancies of women with pre-gestational diabetes mellitus, and those complicated with gestational diabetes mellitus A2, multiple pregnancies, congenital malformations and those lacking prenatal care, were excluded. Demographical, clinical, and obstetrical characteristics were recorded, and pregnancy complications and adverse perinatal outcomes were compared between the groups. Multivariate logistic regression models were used to control for confounders. Statistical analyses were performed using logistic regression to control for potential confounders. A p-value of < 0.05 was considered statistically significant. During the study period, 6254 deliveries met the inclusion criteria, 10.23% of them (n = 640) had diet-controlled GDM. Pregnancies with diet-controlled GDM were found to be associated with significantly higher rates of hypertensive disorders of pregnancy (15.6% vs. 9.8%, p < 0.001), polyhydramnios (5.9% vs. 2.7%, p < 0.001), and cesarean deliveries (40.8% vs. 31.9%, p < 0.001). Diet-controlled GDM was also found to be an independent protective factor against perinatal mortality (aOR = 0.22, 95% Cl 0.05-0.92, P = 0.04) possibly due to the more intensive monitoring and management typically provided to women undergoing fertility treatments. This close care may mitigate some of the risks associated with ART, leading to improved perinatal outcomes. Among pregnancies achieved after fertility treatments, diet-controlled GDM was associated with reduced perinatal mortality and higher rates of certain pregnancy complications. These findings highlight the importance of close monitoring and careful management of women with diet-controlled GDM, as it may help mitigate risks associated with ART pregnancies. Further research is needed to understand the mechanisms behind these outcomes and to optimize management strategies for this specific population.