Gestational hyperglycaemia in Malaysia: early screening and intervention to improve outcomes of pregnancy

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High blood glucose levels in pregnancy or 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 Malaysian 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". At present, all pregnant women in Malaysia are supposed to be screened for GDM because the population is considered to be high-risk. However, doing OGTTs can be challenging. The test requires pregnant women to come to a laboratory 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 higher body weight and older age. However, selecting women based on these factors can miss up to half of all women with GDM. 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 Malaysian women.The aims of this study is to find out whether HbA1c 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 all pregnant women with testing only those with risk factors. We will do a trial to see if a drug called metformin can prevent women developing GDM. Metformin is safe in pregnancy.An accurate HbA1c level 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 level 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 Malaysia. They can focus care more on women at high risk. The results could be used by other countries.