Gestational diabetes: what it means, the OGTT and life after delivery
In this article
Gestational diabetes (GDM) is high blood sugar that appears for the first time in pregnancy, when your body cannot make enough insulin to meet the extra demand. HealthHub says it affects 1 in 5 pregnant women in Singapore. It usually causes no symptoms, so KKH says every pregnant woman here is offered a glucose tolerance test between 24 and 28 weeks.
| How common | 1 in 5 pregnancies in Singapore, HealthHub says |
|---|---|
| Test | Oral glucose tolerance test (OGTT) |
| When | 24 to 28 weeks, or earlier if you are higher risk |
| Treatment | Food and exercise first; tablets or insulin if needed |
| After birth | A repeat OGTT 6 to 12 weeks after delivery |
What happens at the OGTT
KKH describes the test. You fast overnight, with water only. Blood is taken in the morning, you drink a standard 75 g glucose drink, and blood is taken again 1 hour and 2 hours later. You have GDM if any one of those three readings is higher than expected.
The drink is very sweet. KKH says it can make you feel queasy and, rarely, vomit, in which case the test is rebooked for another day. If you have had GDM before, have sugar in your urine or have symptoms of diabetes, KKH tests you earlier in pregnancy and again at 24 to 28 weeks if the first result is normal.
Who is more likely to get it
KKH lists the main risk factors: a BMI of 23 or above, a parent, brother, sister or child with diabetes, GDM in an earlier pregnancy or a baby who weighed over 4 kg, and past pregnancy problems linked to diabetes such as stillbirth. It can still happen to anyone, which is why everyone is screened. KKH puts the figure higher than HealthHub, saying it can occur in nearly a quarter of pregnant women.
How gestational diabetes is treated
KKH says GDM usually improves with healthy eating and exercise, with a dietitian to help you plan meals. You learn to check your sugar with a glucometer before meals, two hours after meals and at bedtime. If your levels stay very high, you may need tablets or insulin injections.
Expect more appointments. KKH checks your blood pressure and urine at every visit because GDM raises your risk of pre-eclampsia, and you may have extra scans to follow your baby's growth. HealthHub says your doctor may suggest induction at term, typically 38 to 39 weeks, if you need medicine, your baby is expected to be large or your sugar is hard to control. Our full guide to gestational diabetes in Singapore has the test cut-offs and home targets, and our pregnancy weight gain calculator helps you keep an eye on your gain.
What it means for your baby
With good sugar control, HealthHub says most mothers with GDM have smooth deliveries and healthy babies. When it is poorly controlled, the baby may grow large, which can make birth harder. HealthHub adds that babies are more likely to need the neonatal unit for low blood sugar, breathing problems or jaundice, and have a higher chance of becoming overweight or developing diabetes later in life.
After your baby is born
NUH says to repeat the OGTT 6 to 12 weeks after delivery, because a small number of women still have abnormal results. Most women can stop their tablets or insulin after the birth, KKH says, and breastfeeding is encouraged.
The follow-up matters. HealthHub says women in Singapore who had GDM are 12 times more likely to develop type 2 diabetes within 5 years of delivery. KKH says that even with a normal test after birth there is a one in three chance of diabetes later, and advises a diabetes check every year.
Frequently asked questions
What is gestational diabetes?
Diabetes that starts during pregnancy. Pregnancy hormones make your body resist insulin, and if your body cannot make enough extra insulin, your blood sugar rises. KKH says it usually starts in the second or third trimester.
Can I say no to the OGTT?
You can. KKH strongly encourages the test because GDM is common and has no symptoms, but it says declining will not affect the rest of your antenatal care. Tell your doctor your reasons so they can talk them through with you.
Does gestational diabetes go away after birth?
Usually. HealthHub says most of the time it is gone by six weeks after delivery, but some women turn out to have diabetes or pre-diabetes and need follow-up.
Will I get gestational diabetes again in my next pregnancy?
You are more likely to. HealthHub says women who had GDM have a higher risk of it in future pregnancies, and KKH tests women with past GDM earlier in the next pregnancy.
Related terms
- Pre-eclampsia: High blood pressure in pregnancy, usually with protein in the urine, most often from 20 weeks.
- Induction of Labour: Starting labour with medical help, such as a pessary, balloon or drip, instead of waiting for it to begin.
- Gestational Hypertension: New high blood pressure that starts after 20 weeks of pregnancy in someone whose blood pressure was normal before.
- Antenatal (also Prenatal): Antenatal means before birth. Antenatal care is the check-ups, scans and tests you get while you are pregnant.
- Neonatal Jaundice: Yellowing of a newborn's skin and eyes from bilirubin. Common and usually mild, but checked in every baby.
- Trimester: One of the three stages of pregnancy, each about three months long.
