Pregnant women with type 1 diabetes are challenging to manage and have a higher risk of adverse outcomes, such as cesarean section, stillbirth, preeclampsia, fetal malformation, and large for gestational age (LGA) infants.1., 2., 3., 4. Optimal glycemic control before and during pregnancy is recommended in such patients, and glycemic targets are achieved when insulin and an adequate diet are combined. Glycemic levels are most frequently monitored through the self-monitoring of blood glucose (SMBG) and glycated hemoglobin (HbA1C) levels.2,5 Nonetheless, HbA1C levels may not adequately reflect fetal exposure to glucose since they represent the average glucose levels during the last 2–3 months; therefore, they do not capture daily glucose fluctuations.2,5,6 SMBG complements HbA1c levels as a dynamic record; hence, it is the main tool used by patients and healthcare professionals to understand the effects of diet, physical activity, and medications on daily glycemic levels.7., 8., 9. Recently, continuous glucose monitoring (CGM) has been used with increasing frequency during pregnancy, and novel targets based on CGM data, such as time in range (TIR), have become standardized as they provide information associated with patterns of hyperglycemia, hypoglycemia, and glycemic fluctuations over time.10,11 During pregnancy, target glucose levels are between 63 mg/dL and 140 mg/dL (3.5–7.8 mmol/L), and the goal is to increase the TIR while reducing the time above range (TAR), time below range (TBR), and glycemic variability.10 In 2019, The Advanced Technologies & Treatments for Diabetes consensus recommended targets for achieving a TIR of >70 %, TAR of <25 %, and TBR of <4 % as early as possible during pregnancy.10 Using CGM, Feig et al. and Kristensen et al. showed that pregnant women with type 1 diabetes were capable of reaching these glycemic targets at the end of the third trimester; moreover, TIR and TAR were associated with the occurrence of LGA infants.1,6 Although the use of CGM is increasingly encouraged as it shows greater precision, convenience, and ease of use, it is more expensive and not widely available, especially in low- and middle-income countries. Therefore, SMBG continues to be the primary method for evaluating glycemic levels in most patients with type 1 diabetes.12,13 In pregnant women, maintaining glycemic levels within the target range is a relevant parameter that influences fetal weight gain. Considering the reality of healthcare systems in Brazil and other low- and middle-income countries, where access to continuous glucose monitoring system (CGMS) resources is limited, SMBG remains the most viable and accessible option for glycemic monitoring. However, to the best of our knowledge, it is unknown whether the concept and goals of TIR can be extrapolated to SMBG measurements to assess the risk of excessive fetal weight gain in pregnant women with type 1 diabetes. Therefore, this study aimed to evaluate the association between extrapolated TIR (eTIR), extrapolated TAR (eTAR), and extrapolated TBR (eTBR), measured using SMBG, and LGA infants in pregnant patients with type 1 diabetes.