Gestational diabetes (GDM) is a type of diabetes that develops during pregnancy. It can happen at any stage of pregnancy, but is more common in the second or third trimester.
During pregnancy, there is increased hormones such as cortisol and estrogen to help your baby grow. However, these hormones can cause your body to become resistant to the effects of insulin.
Normally, the pancreas can produce enough insulin to overcome this resistance. GDM occurs when the body cannot produce enough insulin to meet the increased demands during pregnancy.
In Singapore, one in five pregnant women are affected by GDM.
Risk factors for GDM include:
GDM usually does not cause any symptoms and most cases are diagnosed only when blood glucose levels are tested during pregnancy.
GDM is detected using an oral glucose tolerance test (OGTT). This test is usually done between the 24th and 28th week of pregnancy. If you have any risk factors for GDM, you may be offered an OGTT earlier in the pregnancy.
The OGTT requires fasting for at least eight to 12 hours prior to the test (you may drink water during this period). This is followed by blood tests before and after consuming a glucose drink. The test is done in the morning and usually lasts for two hours. GDM is diagnosed when blood sugar levels are higher than normal before or after the glucose drink.
Most women with GDM have normal pregnancies and healthy babies. However, if GDM is not well-managed, it can cause problems for both you and your baby during pregnancy and after birth.
During pregnancy, the consistently high sugar level in the blood can cross the placenta and stimulate the baby’s growth, making them bigger. Larger babies can lead to difficulties during delivery and increase the likelihood of induced labour or a caesarean section. High blood sugar levels in the mother can also cause babies to develop low blood sugar levels (hypoglycaemia) or jaundice (yellow skin) after birth.
Women with GDM are at increased risk of developing diabetes, fatty liver disease, and cardiovascular disease during their lifetime.
After pregnancy, pregnancy hormone levels rapidly decrease, which resolves insulin-resistance in many women with GDM. However, some women may progress to develop diabetes or pre-diabetes after pregnancy. Therefore, it is important for all women with GDM to have regular follow-up tests for diabetes after pregnancy and before becoming pregnant again.
All women with GDM are recommended to have an oral glucose tolerance test (OGTT) to determine their diabetes status at around six to 12 weeks after giving birth. If the result is normal, women with GDM should still have a yearly blood test for diabetes for the next three years.
If diagnosed with diabetes, treatment should be started as soon as possible. It is important to continue a balanced diet, maintain a healthy weight, and exercise regularly during this period.
Risk factors for women with GDM developing into diabetes include:
Attend your postpartum clinic follow up and perform the OGTT after pregnancy to determine your diabetes status so that you can start treatment early if necessary.
Physical activity helps improve insulin sensitivity and keeps your blood sugar levels in check. We recommend maintaining a reasonable level of fitness with one or more of the following methods:
A balanced diet helps you meet all your nutritional needs. It includes foods from five groups: vegetables, protein, grains, fruits, and dairy. You can also consult a dietitian to develop a meal plan that helps prevent diabetes.
