INTRODUCTION Gestational diabetes mellitus (GDM) is a common metabolic disorder linked to adverse pregnancy outcomes. Recent research indicates that HbA1c is reliable in detecting maternal glycemia during the first trimester but may underestimate glucose intolerance in the late second to third trimesters. Therefore, it is reasonable to hypothesize that mothers with GDM, despite apparently normal HbA1c levels in the third trimester, may give birth to infants displaying characteristic features often seen in infants of diabetic mothers with suboptimal glycemic control. This study aimed to describe a case series of autopsy cases involving stillborn or deceased neonates delivered in the third trimester to mothers diagnosed with GDM and having normal HbA1c levels at or around the time of delivery. The primary focus was on identifying and documenting the characteristic features commonly associated with "infants of diabetic mothers" with suboptimal glycemic control in this series of cases. MATERIALS AND METHODS We conducted a retrospective review of autopsy reports from our institution spanning 7.5 years. The study included cases that met the following criteria: (1) stillborn or infants who died in the early neonatal period, delivered in the third trimester; (2) mothers diagnosed with GDM; (3) normal maternal HbA1c levels of ≤6.1% at or around the time of delivery; (4) birthweight or femoral length exceeding the 90th percentile for gestational age; and (5) absence of genetic aberrations. We also examined these cases for other characteristic features associated with "infants of diabetic mothers." RESULTS Ten autopsy cases met our inclusion criteria, including 9 stillbirths and 1 neonatal death. Gestational age at delivery ranged from 32 to 39 weeks (mean: 35.7 weeks). Femoral length exceeded the 90th percentile in all cases, and 6 cases had birthweights above the 90th percentile. Puffy facies were observed in 6 cases. Among the 9 cases with complete autopsies including internal examination, 6 exhibited excess adipose tissue, 4 had cardiomegaly, and 3 showed pancreatic islet hyperplasia. Hypoxic-ischemic encephalopathy was detected in 7 cases. No structural abnormalities were noted. DISCUSSION Our findings demonstrated that fetuses and neonates born to mothers with apparently normal HbA1c levels in the third trimester could still display characteristic features commonly observed in infants of diabetic mothers with poor glycemic control, also known as "infants of diabetic mothers." This study underscores the potential of third-trimester maternal HbA1c measurements to underestimate maternal glycemia and its consequential impact on fetal development, as well as the subsequent manifestation of features of "infants of diabetic mothers."

中文翻译：

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妊娠晚期的母亲血红蛋白 A1c 可能会低估母亲的高血糖及其对与妊娠糖尿病相关的围产期死亡的后代的影响：尸检病例系列。

简介 妊娠期糖尿病 (GDM) 是一种常见的代谢性疾病，与不良妊娠结局相关。最近的研究表明，HbA1c 在检测妊娠早期的母体血糖方面是可靠的，但可能会低估妊娠中期至晚期的葡萄糖耐受不良。因此，我们可以合理地推测，患有 GDM 的母亲尽管在妊娠晚期的 HbA1c 水平明显正常，但生下的婴儿可能表现出血糖控制不佳的糖尿病母亲的婴儿常见的特征。本研究旨在描述一系列尸检病例，涉及妊娠晚期诊断为 GDM 且在分娩时或分娩前后 HbA1c 水平正常的母亲所生的死产或死亡新生儿。主要重点是识别和记录这一系列病例中血糖控制不佳的“糖尿病母亲的婴儿”通常相关的特征。材料和方法 我们对我们机构 7.5 年的尸检报告进行了回顾性审查。研究纳入的病例符合以下标准：（1）死产或在新生儿早期死亡的婴儿，在妊娠晚期分娩；(2) 诊断患有GDM的母亲；(3) 分娩时或分娩前后正常母亲 HbA1c 水平≤6.1%；(4) 出生体重或者股骨长度超过胎龄第90个百分位；(5) 不存在遗传畸变。我们还检查了这些病例中与“糖尿病母亲的婴儿”相关的其他特征。结果 10 例尸检病例符合纳入标准，其中 9 例死产，1 例新生儿死亡。分娩时孕周为 32 至 39 周（平均：35.7 周）。所有病例的股骨长度均超过 90%，其中 6 例的出生体重超过 90%。6例出现浮肿面容。9例尸检包括内检在内的完整病例中，6例显示脂肪组织过多，4例心脏扩大，3例显示胰岛增生。缺氧缺血性脑病7例。没有发现结构异常。讨论 我们的研究结果表明，妊娠晚期 HbA1c 水平明显正常的母亲所生的胎儿和新生儿仍可能表现出血糖控制不佳的糖尿病母亲的婴儿（也称为“糖尿病母亲的婴儿”）常见的特征。这项研究强调了妊娠晚期母亲 HbA1c 测量可能会低估母亲血糖及其对胎儿发育的影响，以及随后“糖尿病母亲的婴儿”特征的表现。