Free Diabetes TrackerWhat is gestational diabetes?
Gestational diabetes is high blood sugar that develops during pregnancy, usually in the second or third trimester, in women who did not have diabetes before. For most women it goes away soon after the baby is born.
It happens because the hormones of pregnancy make your body more resistant to insulin, the hormone that keeps blood sugar in range. When the body cannot keep up, blood sugar rises. This is nobody's fault – it is a normal part of how some pregnancies work.
Who is more likely to get it?
You may be more likely to develop gestational diabetes if you:
- are above a certain weight;
- have had a large baby in a previous pregnancy;
- have a parent, brother or sister with diabetes;
- are of South Asian, Black, African-Caribbean or Middle Eastern background.
If you have any of these, your maternity team usually offers a glucose tolerance test (an “OGTT”), where your blood sugar is checked after a sugary drink. This is how gestational diabetes is normally found.
Why it matters
If blood sugar stays high, your baby can grow larger than usual, which can make the birth more difficult. Keeping your blood sugar in range through the pregnancy lowers that chance. The good news is that gestational diabetes responds very well to treatment, and many women manage it with small everyday changes.
Your blood sugar targets in pregnancy
The targets in pregnancy (NICE guideline NG3) are tighter than the usual ones. Aim for a reading below these levels:
| When you test | Aim for |
|---|---|
| Fasting (on waking) | below 5.3 mmol/L |
| 1 hour after a meal | below 7.8 mmol/L |
| Or, if you measure at 2 hours after a meal | below 6.4 mmol/L |
At the same time, try to keep your blood sugar above 4 mmol/L so you do not go too low (a hypo). These same targets are used for women who already have type 1 or type 2 diabetes and become pregnant.
Set these targets with your team
The tighter pregnancy targets should always be set and supervised by your maternity or diabetes team, because the right numbers can differ from one person to the next. In the app you can choose “Gestational” as your diabetes type so the target ranges match the ones here – set it up on your tracker.
How it is managed
Management often starts with changes to what you eat and how active you are. If that is not enough to reach your targets, your team may add metformin tablets, insulin, or both. These are safe to use in pregnancy and your team will guide you.
You will usually be asked to test your own blood sugar several times a day – typically first thing in the morning and after meals – so you and your team can see how well things are working and adjust if needed.
After the birth
Gestational diabetes usually goes away once the baby is born, and your blood sugar is checked after the birth to confirm it has settled. Having had it does mean you have a higher chance of developing type 2 diabetes later in life, so an annual blood test called HbA1c is recommended to keep an eye on things.
A yearly check is worth keeping up
Even after a healthy birth, booking that once-a-year HbA1c test is one of the simplest ways to catch any change early, while it is easiest to act on.
Checked against NHS and NICE guidance on . See all official sources.