Gestational Diabetes in Singapore: OGTT, Diet and Aftercare

Gestational diabetes (GDM) is high blood sugar that develops during pregnancy, and it is very common in Singapore: local guidance estimates it affects about one in four to one in five pregnant women. That is why every mum here is offered a 75g glucose tolerance test (OGTT) between weeks 24 and 28.

A diagnosis can feel alarming, but most mums manage GDM well with changes to diet, activity and, for some, medication. This guide explains why Asian mums are at higher risk, how the test works, how to eat with familiar local foods, what monitoring involves, and why follow-up after birth matters.

What is gestational diabetes?

During pregnancy, hormones from the placenta make your body more resistant to insulin, the hormone that moves sugar from your blood into your cells. Most women make extra insulin to compensate. If your body cannot keep up, blood sugar rises, and that is gestational diabetes. It usually appears in the second half of pregnancy and, for most women, goes away after birth.

Left untreated, high blood sugar can cause your baby to grow very large, raising the chance of a difficult birth or caesarean. It is also linked to pre-eclampsia, excess amniotic fluid, and low blood sugar in the baby after birth. The good news: treatment clearly reduces these risks. KKH has reported that its GDM programme, started in 2016, cut poor outcomes linked to poorly managed GDM, such as stillbirth and very large babies, by about half.

Why are Singapore and Asian mums at higher risk?

Singapore’s rate is higher than that of many neighbouring countries. Researchers point to several likely reasons, which often overlap:

Body composition. Asian people tend to carry more body fat, especially around the tummy, at a lower weight or BMI, which is linked to insulin resistance. This is why Singapore uses a lower BMI threshold (23 and above) as a risk factor.
Insulin production. Studies suggest many East and South Asian women produce less insulin in reserve, so they reach their limit sooner in pregnancy.
Diet. Many everyday meals are heavy in white rice, noodles and sweet drinks.
Older mothers. Many Singapore women have babies in their thirties and forties, and risk rises with age.
Family history. Type 2 diabetes is common in Singapore, and it runs in families.

Other risk factors include having had GDM before, polycystic ovary syndrome (PCOS), previously having a large baby, high blood pressure and pre-diabetes. If you have these, your doctor may test you in the first trimester as well as at 24 to 28 weeks.

The OGTT: how you are tested

Singapore’s clinical guidance recommends a 75g OGTT for every pregnant woman not already known to have diabetes, between weeks 24 and 28. You fast overnight (usually from about 10pm, water only), have a blood test, drink a sweet glucose solution within a few minutes, then have blood taken again at one and two hours. You must stay seated in the clinic throughout, so bring a book and a snack for afterwards.

Blood test	GDM is diagnosed if the result is at or above
Fasting	5.1 mmol/L
1 hour after the drink	10.0 mmol/L
2 hours after the drink	8.5 mmol/L

Only one value needs to be high for a diagnosis. These are the internationally used IADPSG criteria adopted in Singapore’s guidance; your clinic will explain your own results. For where the OGTT sits among your other tests, see our guide to pregnancy scans and tests in Singapore.

Eating well with gestational diabetes

You will usually be referred to a dietitian. The aim is not to cut out carbohydrates, which you and your baby still need, but to spread them evenly across the day and choose ones that raise blood sugar more slowly.

Simple principles

Eat three smaller meals and two to three snacks, rather than large meals.
Keep carbohydrates to about a quarter of your plate, fill half with vegetables and a quarter with protein.
Pair carbohydrates with protein, fibre or healthy fats, which slow the sugar rise.
Cut out sugary drinks completely. This single change often makes the biggest difference. If sweet cravings make this hard, try these healthier swaps for cravings.
A 10 to 15 minute walk after meals helps bring sugar levels down.

Local swaps that help

Instead of	Try
A full plate of white rice	Half a bowl of brown or mixed rice, with extra vegetables
Kopi or teh with condensed milk, bubble tea, fruit juice	Kopi-C kosong, teh-O kosong, plain water or unsweetened soya milk
Nasi lemak with fried chicken and extra sambal	Economy rice with one protein, two vegetables, less gravy and a small portion of rice
Mee pok or bee hoon soup with little else	Yong tau foo soup with plenty of tofu, vegetables and a small portion of noodles
Roti prata with sugar	Thosai or chapati with dhal
Kueh, cakes or a big bowl of dessert	A small fruit such as guava, an apple or a pear, plus a handful of nuts

Fruit is fine in small portions, spread across the day, but go easy on very sweet local fruits such as durian, mango, jackfruit and longan. Our guide to what to eat during pregnancy has more hawker-friendly ideas.

Monitoring and treatment

After diagnosis, you will usually be taught to check your blood sugar at home with a finger-prick meter, commonly first thing in the morning and after meals. Your care team will give you target ranges and tell you how often to test. Keep a log, or use the app your clinic recommends, and bring it to every visit.

Many women keep their sugars in range with diet and activity alone. If levels stay high, your doctor may add insulin injections or, in some cases, a tablet such as metformin. Needing medication is not a failure; it simply means your body needs more help, and it protects your baby.

You may also have extra growth scans to check your baby’s size, and your doctor will discuss the timing of birth. Women with well-controlled GDM can often go into labour naturally or be induced around their due date, but plans vary.

After your baby is born

Your baby’s blood sugar will be checked in the first hours after birth, and early, frequent feeding helps keep it stable. Our breastfeeding guide for new mums covers getting started.

For most women, blood sugar returns to normal soon after delivery, and you can stop monitoring and medication as advised. But GDM is an early warning sign: you have a much higher chance of GDM in a future pregnancy and of developing type 2 diabetes later in life.

Have a repeat 75g OGTT between 6 and 12 weeks after birth, as recommended in Singapore’s guidance. Ask for it at your postnatal review if it has not been booked.
If that is normal, get screened for diabetes every one to three years, ideally yearly.
Breastfeeding, staying active and returning gradually to a healthy weight all help lower your long-term risk.
Before your next pregnancy, see your doctor for an early check.

Our postpartum recovery guide explains what else happens at the postnatal check.

The bottom line

Gestational diabetes is common in Singapore, especially among Asian mums, and it is very treatable. Do your OGTT at 24 to 28 weeks, work with your dietitian on balanced local meals, cut sugary drinks, check your sugars as advised and take any medication you need. Then follow up after birth, because your long-term health matters too. The Agency for Care Effectiveness has a useful summary of Singapore’s GDM screening and follow-up guidance.

Can I still eat rice if I have gestational diabetes?

Yes. You need some carbohydrates. Keep rice to a smaller portion, try brown or mixed rice, pair it with protein and vegetables, and spread carbohydrates across the day. Your dietitian can give you a personal guide.

Will my baby have diabetes if I have GDM?

Babies are not born with diabetes because of GDM, but they may have low blood sugar after birth, which is checked and treated. Children of mums with GDM may have a higher chance of weight and sugar problems later, so healthy family habits help.

Does gestational diabetes go away after birth?

For most women, yes. But you should have a repeat OGTT 6 to 12 weeks after birth and regular diabetes checks afterwards, because your risk of type 2 diabetes is higher.

Can I refuse insulin?

You can discuss any treatment with your doctor, but if diet and exercise are not keeping your sugars in range, insulin is safe for your baby and protects you both. Ask about all your options.