Comparison of two Screening Strategies for Gestational Diabetes

描述（由申请方提供）：妊娠期间发生的糖代谢受损（妊娠期糖尿病（GDM）和轻度高血糖症）与妊娠并发症风险增加相关，也是导致糖尿病和心血管疾病的长期代谢功能障碍的早期指征。在美国，GDM通常使用两步筛查和诊断方法进行诊断。国际糖尿病和妊娠研究组协会（IADPSG）提出了一种一步诊断方法，通过降低临界值来扩大GDM的定义，以包括患有轻度高血糖症的女性，这些女性在目前的两步方法下筛选正常。这些建议的目的是更好地识别有妊娠并发症和长期代谢功能障碍风险的妇女，但它导致GDM患病率显著增加。NIH GDM共识发展会议委员会不建议将目前的两步筛查/诊断方法改为IADPSG一步诊断方法，除非试验证明增加诊断为GDM的女性数量会导致更好的结果。在本申请中，我们的目标是：1）进行一项“真实的世界”随机对照试验（RCT），以确定两种主要GDM筛查方法之间GDM检测的短期围产期健康结局的差异，以及2）前瞻性随访母亲，以检查她们的代谢风险特征和产后一年婴儿的生长情况。基于一项初步可行性研究，我们提出了一项单中心盲法随机对照试验，纳入了920名年龄在18-45岁之间、妊娠18-24周、未诊断为糖尿病的单胎妊娠孕妇。受试者将在妊娠24-28周之间进行非空腹1小时50 gm葡萄糖激发试验（GCT）。50 gm GCT结果< 200 mg/dL的女性将随机接受空腹2小时75 gm口服葡萄糖耐量试验（OGTT）或3小时100 gm OGTT。对于接受75 gm OGTT的女性，使用IADPSG标准诊断GDM，对于接受100 gm OGTT的女性，使用Carpenter-Coustan标准诊断GDM。参与者及其医生将被告知GDM的诊断，但将对用于诊断的特定测试结果和标准保持盲态。GDM受试者将接受由其主治医生或助产士决定的治疗，所有受试者将继续进行常规产前护理。简短的问卷调查将用于评估参与者和医生对GDM测试的看法。将在随机化和产后一年评估受试者的代谢特征。主要结局指标是大于胎龄胎儿生长。拟议研究的理由是，这是一个比较这两种方法的独特机会。在研究结束时，我们将知道根据IADPSG标准诊断为血糖水平较低的妇女是否更有可能发生不良围产期结局。我们的假设是，使用IADPSG诊断标准将导致检测到更多的妇女与糖代谢受损，治疗这些妇女将减少不良围产期结局，并防止长期代谢功能障碍。这项研究将提供基于A级证据的数据，以评估两种筛查方法，以便GDM筛查的通用指南可以得到主要组织的认可并实施到临床护理中。

DESCRIPTION (provided by applicant): Impaired glucose metabolism (gestational diabetes (GDM) and mild hyperglycemia) that occurs during pregnancy is associated with an increased risk for pregnancy complications and is also an early indication of long- term metabolic dysfunction leading to diabetes and cardiovascular disease. In the US, GDM is commonly diagnosed using a two-step screening and diagnostic approach. The International Association of Diabetes and Pregnancy Study Group (IADPSG) proposed a one-step diagnostic approach that broadens the definition of GDM by lowering the cutoff values to include women with milder forms of hyperglycemia, who would have screened normal under the current two-step approach. The goal of these recommendations is better identification of women at risk for pregnancy complications and long-term metabolic dysfunction, but it results in a significant increase in the prevalence of GDM. The NIH Gestational Diabetes Consensus Development Conference committee does not recommend changing from the current two-step screening/diagnostic approach to the IADPSG one-step diagnostic approach without trials demonstrating that increasing the number of women diagnosed as having GDM results in better outcomes. In this application, we aim to 1) conduct a "real world" randomized controlled trial (RCT) to determine differences in short-term perinatal health outcomes with GDM testing between the two predominant GDM screening approaches, and 2) prospectively follow the mothers to examine their metabolic risk profiles and the growth of their infants at one year postpartum. Based on a pilot feasibility study, we propose a single site blinded RCT of 920 pregnant women at 18-24 weeks' gestation between ages 18-45 years who have not been diagnosed with diabetes, with a singleton pregnancy. Participants will have a non-fasting 1 hour 50 gm glucose challenge test (GCT) performed between 24-28 weeks' gestation. Women with 50 gm GCT results < 200 mg/dL will be randomized to receive either a fasting 2 hour 75 gm oral glucose tolerance test (OGTT) or a 3 hour 100 gm OGTT. GDM will be diagnosed using the IADPSG criteria for women receiving the 75 gm OGTT and Carpenter-Coustan criteria for women receiving the 100 gm. Participants and their physicians will be informed of the diagnosis of GDM, but will be blinded to the specific test results and criteria used to make the diagnosis. Participants with GDM will receive treatment as determined by their primary physician or midwife, and all participants will continue routine prenatal care. Brief questionnaires will be used to assess participants' and physicians' views on GDM testing. Metabolic profiles for participants will be assessed at randomization and at a year postpartum. The primary outcome measure is large-for-gestational age fetal growth. The rationale for the proposed research is that this is a unique opportunity to compare the two methods. At the end of the study, we will know whether women diagnosed at lower glucose levels with the IADPSG criteria are more likely to have adverse perinatal outcomes. It is our hypothesis that using IADPSG diagnostic criteria will result in detection of more women with impaired glucose metabolism and that treating these women will reduce adverse perinatal outcomes and prevent long-term metabolic dysfunction. This study will provide data grounded in level A evidence, to evaluate the two screening methods so universal guidelines for GDM screening can be endorsed by major organizations and implemented into clinical care.