Protocol Summary/Abstract In the setting of increasing prevalence of obesity and pre-diabetes, there is growing interest in identification of hyperglycemia in early pregnancy to facilitate treatment and minimize fetal exposure. Although multiple organizations recommend first trimester diabetes screening among individuals with risk factors, the benefits and drawbacks of detecting glucose abnormalities short of frank diabetes and optimal screening method in early gestation remain unclear. The overarching goal of the NIDDK-supported ChartGlucose4Moms: Characterizing, by Trimester, Continuous Glucose Monitoring Measurements for determining effects on Maternal & Offspring Metabolic Sequelae study (aka, Glycemic Observation and Metabolic Outcomes in Mothers and offspring (GO MOMs) study) is to evaluate how early pregnancy glycemia, measured using continuous glucose monitoring (CGM) and oral glucose tolerance testing (OGTT), relates to gestational diabetes (GDM) diagnosis at 24-28 weeks' gestation (maternal primary outcome) and large-for-gestational-age (newborn primary outcome). A secondary objective is to perform comprehensive, longitudinal assessment of changes in glucose over the course of pregnancy. Enrollment began in April 2021 and will continue for 3.5 years with a target sample size of 2150 participants (200 of which are being recruited at KPNW). GO MOMs will yield data that are vital to improving our understanding of hyperglycemia in pregnancy, facilitate improved approaches for GDM screening in early pregnancy, and inform future clinical trials of early GDM treatment.