Abstract Context The excess risk of fatal and nonfatal cardiovascular events is roughly twice as high in women than in men with type 1 diabetes. Objective To evaluate the impact of preeclampsia and parity on sex-based discrepancies in preclinical atherosclerosis and on the diagnostic performance of a cardiovascular risk scale. Design Cross-sectional study. Setting Single tertiary hospital. Patients A total of 728 people with type 1 diabetes (48.5% women) without cardiovascular disease and age ≥40 years, nephropathy, and/or ≥10 years of diabetes duration with another risk factor. Intervention Standardized carotid ultrasonography. Main Outcome Measures Carotid plaque determined by ultrasonography and cardiovascular risk estimated according to the Steno T1 Risk Engine (Steno-Risk). Results Nulliparous women and parous women without previous preeclampsia had a lower risk for carotid plaque than men (adjusted odds ratio: .48, 95% confidence interval [.28-.82]; adjusted odds ratio: .51 [.33-.79], respectively), without differences in the preeclampsia group. The prevalence of carotid plaque increased as the estimated cardiovascular risk increased in all subgroups except for preeclampsia group. The area under the curve of the Steno-Risk for identifying ≥2 carotid plaques was lower in the preeclampsia group (men: .7886; nulliparous women: .9026; women without preeclampsia: .8230; preeclampsia group: .7841; P between groups = .042). Neither the addition of parity nor preeclampsia in the Steno-Risk led to a statistically significant increase in the area under the curve. Conclusion The risk for carotid plaque in women compared with men decreased as exposure to obstetric factors diminished. However, the addition of these factors did not improve the prediction of the Steno-Risk.