To evaluate the association between extrapolated time in range (eTIR), measured by self-monitoring of blood glucose (SMBG), and large-for-gestational-age (LGA) infants in pregnancies with type 1 diabetes (T1D). Retrospective cohort analysis including singleton pregnancies with T1D who started antenatal care before 20 gestational weeks and delivered live newborns at a Brazilian hospital between 2010 and 2019, with LGA fetuses as the main outcome. Glycemic records acquired using SMBG were categorized as eTIR, extrapolated time below range (eTBR), and extrapolated time above range (eTAR). Women were divided into two groups (LGA and adequate for gestational age [AGA]) and compared regarding clinical characteristics, obstetric outcomes, and frequencies of eTIR, eTBR, and eTAR. Logistic regression analysis verified the independent predictive variables for LGA infants. Data from 125 pregnancies were analyzed. For the first, second and third trimesters, each 1 % increase in eTIR was associated with a decreased risk of LGA by 2.9 % (OR: 0.971; 95%CI: 0.945–0.998), 2.5 % (OR: 0.975; 95%CI: 0.951–0.999) and 2.3 % (OR: 0.977; 95%CI: 0.955–0.998) and each 1 % increase in eTAR was associated with an increased risk of LGA by 2.7 % (OR: 1.027; 95%CI: 1.005–1.050), 3.9 % (OR: 1.039; 95%CI: 1.014–1.063) and 4.6 % (OR: 1.046; 95%CI: 1.018–1.075), respectively. The concept of TIR can be extrapolated to patients undergoing SMBG to assess the risk of LGA infants in pregnant women with T1D.

中文翻译：

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1 型糖尿病孕妇的外推时间范围与大于胎龄儿之间的关联

旨在评估通过血糖自我监测 (SMBG) 测量的外推时间范围 (eTIR) 与 1 型糖尿病 (T1D) 妊娠中的大于胎龄 (LGA) 婴儿之间的关联。回顾性队列分析包括 2010 年至 2019 年间在巴西一家医院分娩并在 20 孕周前开始产前护理的患有 T1D 的单胎妊娠，其中 LGA 胎儿为主要结果。使用 SMBG 获取的血糖记录分为 eTIR、低于范围的外推时间 (eTBR) 和高于范围的外推时间 (eTAR)。将妇女分为两组（LGA 和足胎龄 [AGA]），并比较临床特征、产科结果以及 eTIR、eTBR 和 eTAR 的频率。逻辑回归分析验证了 LGA 婴儿的独立预测变量。分析了 125 次怀孕的数据。对于妊娠早期、中期和晚期，eTIR 每增加 1%，LGA 风险就会降低 2.9%（OR：0.971；95%CI：0.945–0.998）、2.5%（OR：0.975；95%CI） ：0.951–0.999）和 2.3%（OR：0.977；95%CI：0.955–0.998），eTAR 每增加 1%，LGA 风险增加 2.7%（OR：1.027；95%CI：1.005–分别为 1.050）、3.9%（OR：1.039；95%CI：1.014–1.063）和 4.6%（OR：1.046；95%CI：1.018–1.075）。 TIR 的概念可以推广到接受 SMBG 的患者，以评估患有 T1D 的孕妇生出 LGA 婴儿的风险。