A diagnosis of gestational diabetes can arrive as a surprise appointment letter or a passing comment at a routine scan, and either way it is normal to feel a jolt of worry. Gestational diabetes is a type of diabetes that develops during pregnancy, usually in the second half, when the body finds it harder to manage blood sugar. It generally goes away after birth, though it does mean closer monitoring while you are pregnant.

Who Is Offered Screening

According to NHS guidance on gestational diabetes, you are more likely to be offered screening if your body mass index is above 30, you previously had a baby weighing 4.5kg or more at birth, you had gestational diabetes in an earlier pregnancy, one of your parents or siblings has diabetes, or you are of South Asian, Black, African-Caribbean, or Middle Eastern origin. Your midwife will talk through these risk factors at your booking appointment.

The Screening Test

Gestational diabetes is diagnosed with an oral glucose tolerance test, known as an OGTT. It involves a fasting blood test in the morning, a sugary drink, and a second blood sample two hours later to see how your body handles the glucose. Most people have this between 24 and 28 weeks, though if you have had gestational diabetes before, you will usually be offered an earlier test soon after your booking appointment, with a repeat at 24 to 28 weeks.

How It Can Affect Pregnancy

With good care, most people with gestational diabetes go on to have healthy pregnancies and healthy babies. Left unmanaged, higher blood sugar can increase the chance of a larger than average baby, which can complicate birth, a higher likelihood of induced labour or caesarean birth, and a greater risk of pre-eclampsia. After birth, babies of mothers with unmanaged gestational diabetes may have low blood sugar or jaundice, a yellowing of the skin and eyes, which can need treatment in hospital. This is precisely why monitoring and management matter, and why the condition is taken seriously even though it usually resolves on its own.

In the longer term, both you and your child may have a slightly higher chance of developing type 2 diabetes later in life, though healthy eating, staying active, and keeping up with the follow-up checks your team recommends can reduce that risk considerably. None of this means anything has gone wrong, it simply means your body needs a bit more support to manage glucose than it did before pregnancy.

How It Is Managed

Once diagnosed, you will usually be cared for by a joint maternity and diabetes team. Management typically includes healthy eating that balances carbohydrates, protein, and vegetables, regular gentle activity such as walking, and checking your blood sugar at home with a meter several times a day. Your team will set personal blood sugar targets before and after meals and explain what to do if a reading is outside them.

Food And Drink Tips

Diet advice for gestational diabetes commonly includes limiting sugary foods and drinks such as fizzy drinks, sweets, and cakes, choosing wholegrain carbohydrates like wholemeal bread, brown rice, or wholewheat pasta in modest portions, and avoiding "double carbohydrate" meals such as pasta with garlic bread. Filling half your plate with vegetables or salad, including lean protein such as chicken, fish, eggs, beans, or lentils at each meal, and spacing out fruit through the day rather than having large portions or juices all at once can also help keep levels steadier. Tommy's guide to gestational diabetes has more detail, and your diabetes team or dietitian can tailor advice to your tastes, culture, and budget.

Medicines And Insulin

Some people manage gestational diabetes through diet and activity alone. Others need medicine as well. You might be offered metformin tablets to help your body use insulin more effectively, or insulin injections if tablets are not enough or not suitable for you. Your team will show you exactly how to take any medicine or give any injections safely during pregnancy.

Birth And Afterwards

Your team will plan your birth with you, taking your blood sugar control and any other factors into account. After birth, your baby's blood sugar will be checked, and you will usually be able to feed them soon afterwards. Many people also choose to hand-express and store a little colostrum in the final weeks of pregnancy as extra reassurance around feeding, which our guide to colostrum harvesting in pregnancy explains in detail. Your own blood sugar usually returns to normal within hours or days of birth, and you will be offered a follow-up blood test 6 to 13 weeks later to check that the diabetes has resolved, with ongoing diabetes checks at your GP after that.

The Emotional Side Of A Diagnosis

Extra appointments, home testing, and dietary changes can feel like a lot to take on, especially on top of everything else pregnancy already asks of you. Some people also feel a flash of guilt, as though the diagnosis reflects something they did wrong, which is not the case. Gestational diabetes is caused by pregnancy hormones affecting how your body uses insulin, not by anything you ate or failed to do.

It can help to write down questions before appointments so you get the answers you need, to involve your partner or family in the practical changes to food and activity, and to seek support from your midwife, diabetes nurses, or other people managing the same condition. Many maternity units run peer support groups specifically for gestational diabetes, which can be a good place to swap practical tips as well as reassurance.

Steady Support From Diagnosis To Birth

Gestational diabetes is common, and with monitoring, sensible eating, activity, and treatment where it is needed, most people go on to safe births and healthy babies. Understanding what is happening in your body, why the tests and appointments matter, and how the condition is managed can turn an overwhelming diagnosis into something far more workable. Your care team is there throughout, and asking questions along the way is part of getting the most from that support.

Gestational Diabetes: Signs, Testing, and What Happens Next