Role of HbA1c and 50g GCT in early detection and prediction of gestational diabetes and associated maternal and fetal complications in Thailand

妊娠期高血糖称为妊娠糖尿病（GDM）是妊娠期最常见的医疗条件之一。它可能会对孕妇和孩子造成伤害。GDM影响10-15%的泰国妇女。现在越来越多的妇女被诊断为GDM，因为较低的血糖水平被用来诊断GDM。如果不治疗，GDM会导致妊娠期高血压，增加剖腹产的数量，焦虑和抑郁。患有GDM的女性患2型糖尿病（T2 DM）的终生风险高7-8倍。对孩子来说也有风险。它们可能太大或太小。如果太大，他们可能会在分娩时肩膀受伤。他们的血糖在出生后可能会下降得太低。他们可能会在出生后不久出现黄疸，或呼吸困难。极少数可能在出生前死亡（死产）。妊娠期糖尿病的诊断通常在怀孕24-28周之间进行，使用称为口服葡萄糖耐量试验（OGTT）的葡萄糖饮料试验。虽然治疗可以改善妊娠结局，但一些损害可能已经对未出生的婴儿造成了。因此，在怀孕早期进行筛查以检测高血糖水平可能更好。然而，筛查既有好处也有坏处。正如《英国医学杂志》最近的一篇文章所说：“贴上妊娠糖尿病的标签，就意味着要采取一揽子干预措施，其中包括血糖监测、额外的门诊就诊、更多的产科监测，更有可能进行引产、手术分娩和让婴儿接受特殊护理，最后，母亲还被贴上糖尿病高风险的标签”。有些人认为所有女性都应该接受OGTT筛查，但这可能不是必要的。该测试要求孕妇来诊所至少8小时不吃任何东西。在包括英国在内的许多国家，选择女性进行OGTT是基于超重和年龄较大等风险因素。然而，根据这些因素选择女性可能会错过多达一半的GDM女性。在泰国，GDM高危妇女应该在第一次产前诊所就诊时进行50 g葡萄糖挑战试验（GCT）筛查。但是，泰国的GDM筛查率从农村地区的零到城市的78%不等。另一种通过简单的手指针刺（称为HbA 1c）进行的血糖测试可能会代替。这将在第一次产前门诊检查时进行。HbA 1c是一个单步测试，患者不需要禁食。然而，HbA 1c检测的价值尚不清楚在泰国women.The的目的是找出是否HbA 1c和50克GCT测试在第一次产前诊所访问可以预测以后GDM，如果有一个水平，可以排除以后GDM。我们还希望将所有孕妇的检测与仅检测有风险因素的孕妇进行比较。我们将进行一项试验，看看饮食和生活方式干预是否可以预防女性患GDM。准确的HbA 1c和50 g GCT水平可以安全地排除低风险女性患GDM的可能性，这将有助于孕妇。他们可以放心。避免OGTT的需要将节省他们的时间和金钱。相比之下，如果HbA 1c和50 g GCT水平将他们确定为高风险，健康饮食和生活方式建议可以降低他们患GDM的风险。除了对母亲及其子女有益外，这项研究还将对泰国提供保健的人有用。他们可以把更多的注意力集中在高危女性身上。研究结果可供其他国家使用。

High blood glucose levels in pregnancy called gestational diabetes mellitus (GDM) is one of the most common medical conditions during pregnancy. It can cause harm to the pregnant woman and her child. GDM affects 10-15% of Thai women. More women are being diagnosed with GDM now because a lower level of blood glucose is being used to diagnose GDM.If not treated, GDM can cause high blood pressure in pregnancy, increased numbers of caesarean deliveries, anxiety and depression. Women who have had GDM have 7-8 times higher life-time risk of type 2 diabetes mellitus (T2DM). There are risks to the children too. They may be too big or too small. If too big, they can have shoulders damaged during the birth. Their blood glucose may fall too low after birth. They may get jaundice soon after birth, or have difficulty in breathing. A very few may die before birth (stillbirth). In the long term, these children are at higher risk of becoming overweight and diabetic.The diagnosis of GDM is usually made between 24-28 weeks of pregnancy using a glucose drink test called an oral glucose tolerance test (OGTT). Although treatment can improve pregnancy outcomes, some of the damage may have already been done to the unborn baby. So screening to detect high glucose levels earlier in pregnancy may be better. However, there can be harms as well as benefits from screening. As a recent British Medical Journal article said:"a label of gestational diabetes brings with it an intervention package that includes glucose monitoring, extra clinic visits, more obstetric monitoring with greater likelihood of labour induction, operative delivery and admission of the baby to special care, and finally for the mother a label of high risk for diabetes". Some people think that all women should be screened with OGTT has been advocated but that may not be needed. The test requires pregnant women to come to a clinic having not eaten anything for at least 8 hours. In many countries including the UK, women are selected for OGTT based on risk factors such as overweight and older age. However, selecting women based on these factors can miss up to half of all women with GDM. In Thailand, women at high risk for GDM are supposed to be screened at the first antenatal clinic visit with the 50g Glucose Challenge Test (GCT). But, the rate of screening for GDM in Thailand varies from none at all in rural areas to 78% in cities. Another blood glucose test done by a simple finger prick (called HbA1c) might do instead. It would be done at the first antenatal clinic visit. The HbA1c is a one-step test and patients do not need to fast. However, the value of HbA1c testing is not yet known in Thai women.The aims of this study are to find out whether HbA1c and 50g GCT testing at first antenatal clinic visit can predict later GDM and if there is a level that can rule out later GDM. We also want to compare testing of all pregnant women with testing only those with risk factors. We will do a trial to see if diet and lifestyle interventions can prevent women developing GDM.Accurate HbA1c and 50g GCT levels that can safely rule out GDM in women at low risk would help pregnant women. They can be reassured. Avoiding the need for OGTT would save them time and money. In contrast, if the HbA1c and 50g GCT levels identifies them as at high-risk, healthy eating and lifestyle advice can reduce their risk of getting GDM. In addition to the benefit to mothers and their children, this study will also be useful to people who provide health care in Thailand. They can focus care more on women at high risk. The results could be used by other countries.