Gestational Diabetes: What It Means for You and Your Baby

TL;DR: Gestational diabetes is high blood sugar that develops in pregnancy and usually goes away after birth. In the UK, NICE recommends a glucose tolerance test at 24 to 28 weeks if you have risk factors, including Black African, African-Caribbean, South Asian or Middle Eastern family origin. Most women manage it with diet and activity, some need tablets or insulin, and everyone needs a diabetes check after birth because the risk of type 2 diabetes later is much higher.

Being told you have gestational diabetes can feel like a shock, especially if you feel perfectly well. Suddenly there are finger-prick tests, conversations about what is on your plate, and new words like "induction" in your birth plan. It is easy to feel you have done something wrong. You have not. Pregnancy hormones make it harder for insulin to work, and some bodies simply need more help keeping up. The good news is that gestational diabetes is very treatable, and finding it is the first step to protecting you and your baby.

If you want a wider picture of the checks you will have during pregnancy, our walkthrough of prenatal tests and scans puts the glucose test in context.

What is gestational diabetes?

According to the NHS, gestational diabetes is high blood sugar that develops during pregnancy and usually disappears after giving birth. It can happen at any stage but is more common in the second or third trimester. It happens when your body cannot make enough insulin to meet the extra needs of pregnancy.

Does gestational diabetes cause symptoms?

Usually not. The NHS says most cases are only found through screening. If blood sugar gets very high, some women notice more thirst, needing to pee more often, a dry mouth, tiredness, blurred eyesight, or genital itching and thrush. Many of these are common in pregnancy anyway, which is exactly why testing matters more than waiting for symptoms.

Who gets tested for gestational diabetes?

In the UK, your midwife will ask about risk factors at your booking appointment. Under NICE guideline NG3, you should be offered testing if you have any of these:

• a BMI of 30 or above
• a previous baby weighing 4.5 kg (10 lb) or more at birth
• gestational diabetes in a previous pregnancy
• a parent, brother or sister with diabetes
• a family origin with a high prevalence of diabetes

The NHS spells out that last point: you are at increased risk if you are of south Asian, Black, African-Caribbean or Middle Eastern origin, even if you were born in the UK. It also lists being over 40 and having had weight-loss surgery. For many Black African women in the diaspora, ethnicity alone means you should be offered the test, so if no one mentions it by around 24 weeks, ask.

If you are pregnant in Nigeria, Kenya, Ghana or elsewhere, testing practice varies between hospitals and private clinics. Use the same risk list above and ask your doctor or midwife directly whether and when you will be screened. Our list of questions to ask at antenatal appointments can help you raise it.

How does the glucose tolerance test work?

The test is called an oral glucose tolerance test, or OGTT, and the NHS describes it like this:

1. You have nothing to eat or drink (except usually water) for 8 to 10 hours, typically overnight.
2. In the morning, you have a blood test.
3. You drink a sugary glucose drink.
4. You rest for 2 hours, then have a second blood test.

It takes about two hours, so bring something to read and a snack for afterwards. Most women are tested between 24 and 28 weeks. If you had gestational diabetes before, NICE recommends earlier testing soon after booking, either with home blood sugar monitoring or an OGTT, then a repeat OGTT at 24 to 28 weeks if the first is normal.

NICE diagnoses gestational diabetes if your fasting glucose is 5.6 mmol/l or above, or your two-hour reading is 7.8 mmol/l or above.

How can gestational diabetes affect you and your baby?

Most women with gestational diabetes have otherwise normal pregnancies and healthy babies. But if blood sugar stays high, the NHS lists possible problems including:

• your baby growing larger than usual, which can make birth harder and increase the chance of induction or caesarean
• too much amniotic fluid (polyhydramnios), which can lead to early labour
• premature birth
• pre-eclampsia, a pregnancy blood pressure condition
• your baby having low blood sugar or jaundice after birth
• rarely, stillbirth

Pre-eclampsia deserves a special mention because it can develop quickly. Read our guide to pre-eclampsia warning signs so you know when to call your maternity unit straight away, especially if you have a severe headache, vision changes, pain under your ribs or sudden swelling of your face, hands or feet.

How is gestational diabetes treated?

Treatment is about keeping your blood sugar in a target range, and it usually works well. NICE recommends:

A review within a week. You should be seen by a joint diabetes and antenatal team within one week of diagnosis.

Home blood sugar testing. You will be given a meter and shown how to do finger-prick tests at set times of day.

Diet and activity first. Everyone should be referred to a dietitian. NICE suggests regular exercise, for example walking for 30 minutes after a meal. The NHS also mentions swimming and prenatal yoga, and asks you to check with your midwife before starting anything new.

Medicine if needed. If your targets are not met with diet and exercise within one to two weeks, NICE recommends metformin tablets, and insulin if metformin is not suitable or not enough. Needing medicine does not mean you have failed. It simply means your body needs more support right now.

On food, you do not need to give up the meals you love. A dietitian can help you adapt your own dishes, whether that is rice, yam, eba, fufu or ugali, to fit your targets, and our pregnancy nutrition guide covers the nutrients you still need.

What about birth?

You will usually have extra growth scans and monitoring. NICE advises women with uncomplicated gestational diabetes to give birth no later than 40 weeks and 6 days, so induction or a caesarean may be offered if labour has not started by then. Earlier birth may be recommended if there are concerns about you or your baby. After birth, your baby's blood sugar will be checked, and NICE advises feeding your baby within 30 minutes of birth and then every 2 to 3 hours to help keep it steady. Any diabetes medicine you were taking for gestational diabetes is usually stopped straight after the birth.

What happens after the baby is born?

For most women, blood sugar returns to normal soon after birth. But gestational diabetes leaves a lasting signal. A large meta-analysis in the BMJ found women who had it were nearly 10 times more likely to develop type 2 diabetes than women who did not, with the risk highest in the first years after pregnancy. You are also more likely to have gestational diabetes again in a future pregnancy.

That is why the follow-up matters so much:

• 6 to 13 weeks after birth: NICE recommends a fasting blood glucose test, which can be done around your six-week postnatal check. If it is missed, a fasting glucose test, or an HbA1c test if that is not possible, can be done after 13 weeks.
• Every year after that: an annual HbA1c test, even if everything was normal.
• Before your next pregnancy: get checked for diabetes and ask for early testing next time.

These checks are easy to forget when you are caring for a newborn, so put a reminder in your phone now. In England, the NHS says women with a history of gestational diabetes can self-refer to the NHS Diabetes Prevention Programme for help with diet, exercise and weight. Our guide to prediabetes in women explains how small, steady changes can lower your future risk.

Keeping track

Between appointments, finger-prick readings, scans and new advice can blur together. Asele's symptom logging gives you one place to note how you feel, and the Health Brief turns your notes into a pre-visit summary to share with your midwife or doctor. Amara can explain terms like OGTT or polyhydramnios in Yoruba, Hausa, Igbo, Swahili, French or English. You can find us at Asele.

This post is education, not medical advice. Your maternity team will tailor your care to you, and you should contact them any time you are worried about yourself or your baby's movements.

References

1. NHS. Gestational diabetes. nhs.uk
2. National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period (NG3). nice.org.uk
3. Vounzoulaki E, et al. Progression to type 2 diabetes in women with a known history of gestational diabetes: systematic review and meta-analysis. BMJ, 2020. pmc.ncbi.nlm.nih.gov