# Gestational diabetes: the glucose test and what happens next > What gestational diabetes is, who has the glucose test and when, what the test involves, and how care is planned through pregnancy, birth and beyond. Source: https://www.amalkehail.com/en/articles/gestational-diabetes/ Last updated: 2026-10-26 Pregnancy and birth · 5 min read Gestational diabetes is raised blood glucose that develops during pregnancy and usually goes away after the birth. It is found with a blood test, most often around the middle of pregnancy. This article explains who has the test, what it involves, and what usually follows if it shows gestational diabetes. Written by [Dr Amal Kehail](https://www.amalkehail.com/en/about/) Specialist Obstetrics and Gynecology Updated: 26 October 2026 Medically reviewed by Dr Amal Kehail, 26 October 2026 **Evidence basis:** Based on the NICE guidelines on diabetes in pregnancy (NG3) and antenatal care (NG201), which draw on published studies and expert consensus, and on clinical experience in general obstetric practice. This is general information and does not replace a consultation. ## In short - Gestational diabetes is raised blood glucose that develops during pregnancy and usually causes no symptoms, so it is found by a test, usually done between 24 and 28 weeks. - Care usually begins with food and activity and checking your glucose at home, and medicine is added if glucose stays above target, after its benefits and possible side effects are discussed. - It usually goes away after the birth but leaves a higher chance of type 2 diabetes in later years, so NICE advises a blood glucose test 6 to 13 weeks after the birth, then a yearly test if that is normal. - Seek urgent care if your baby is moving less than you are used to, if signs of low blood glucose do not improve after you treat them in the way you were shown, or if you have signs of pre-eclampsia such as a severe headache or changes in vision. **On this page** 1. Gestational diabetes is raised blood glucose that begins in pregnancy 2. Who has the glucose test, and when 3. What the glucose tolerance test involves 4. What happens if the test shows gestational diabetes 5. Planning the birth, and the checks that follow 6. When to seek urgent care ## Gestational diabetes is raised blood glucose that begins in pregnancy In pregnancy, hormones from the placenta make the body respond less to insulin, the hormone that moves glucose (sugar) from the blood into the cells. If the body cannot make enough extra insulin to compensate, blood glucose rises, and this is gestational diabetes. It usually causes no symptoms, or ones easily mistaken for ordinary pregnancy such as thirst or tiredness, so it is found by testing. Raised glucose crosses the placenta to the baby. Over time the baby may grow larger than expected, which can make the birth more difficult and makes induction or a cesarean more likely. It can also mean extra fluid around the baby, a higher chance of pre-eclampsia, and low blood glucose in the baby after birth. Keeping glucose on target lowers the chance of these problems. ## Who has the glucose test, and when NICE advises the test for pregnant women with at least one of these risk factors: - A body mass index (BMI) above 30. - A previous baby who weighed 4.5 kg or more at birth. - Gestational diabetes in a previous pregnancy. - A parent, brother or sister with diabetes. - A family background in which diabetes is common, including Middle Eastern, South Asian and Black Caribbean families. Because some of these factors are common, some hospitals and clinics test every pregnant woman. The test is usually done between 24 and 28 weeks. Women who had gestational diabetes before are tested soon after the early antenatal visit, with the same test or with home glucose checks, and again at 24 to 28 weeks if that test was normal. Sugar in the urine at a routine check can also lead to testing. [More on this: Antenatal & Postnatal Care](https://www.amalkehail.com/en/clinical-interests/antenatal-postnatal-care/) ## What the glucose tolerance test involves The usual test is the oral glucose tolerance test (OGTT), which takes about two hours. You are asked to have nothing to eat or drink except water for 8 to 10 hours beforehand, so the test is usually done in the morning. A blood sample is taken, you drink a sweet glucose drink, then wait quietly, without eating, for a second sample two hours later. Some women feel slightly sick or light-headed after the drink, and a snack for afterwards can help. If you take regular medicines, ask beforehand whether to take them that morning. In NICE guidance the diagnosis is gestational diabetes when the fasting reading is 5.6 mmol/litre or above (about 101 mg/dL), or the two-hour reading is 7.8 mmol/litre or above (about 140 mg/dL). Hospitals do not all follow the same guideline, so your readings are judged against the range printed on your own report. A normal test is reassuring for that stage, but glucose can rise later, so the test may be repeated if concerns appear. ## What happens if the test shows gestational diabetes Care usually begins with food and activity. A dietitian can help build meals around slower-release carbohydrates such as wholegrains, pulses and vegetables, in place of sugary drinks, sweets, and white bread or rice. A walk after meals helps too. You also learn to check your glucose at home with a finger-prick meter, usually before breakfast and after meals, and the readings are reviewed at each visit. If glucose stays above target after one or two weeks, medicine is added, usually metformin tablets and then insulin if needed. Metformin can cause stomach upset, such as nausea or loose stools, and it does not suit every woman. Insulin may be started sooner if glucose is well above target at diagnosis. Both are widely used in pregnancy, and their benefits and possible side effects are discussed before starting. Insulin can cause low blood glucose, so women using it learn to recognise and treat a low. Extra scans check the baby’s growth and the fluid around the baby, usually every few weeks in the last three months. If you plan to fast in Ramadan, raise it with your doctor well before the month begins. Fasting changes blood glucose through the day and the way medicines, especially insulin, need to be taken. ## Planning the birth, and the checks that follow If all is well, NICE advises giving birth by 40 weeks and 6 days, usually by induction if labour has not started, and earlier if glucose is hard to control or there are concerns about mother or baby. If scans suggest a large baby, induction, waiting for labour and a planned cesarean are discussed, with the benefits and risks of each. During labour, glucose is checked regularly, sometimes with a drip to keep it steady. After the birth, gestational diabetes medicines are usually stopped, and the baby is fed soon and often, with blood glucose checks in the hours that follow. Gestational diabetes usually goes away after the birth, but it leaves a higher chance of type 2 diabetes in later years and of gestational diabetes next time. NICE advises a blood glucose test 6 to 13 weeks after the birth, then a yearly test if that is normal. Keeping active and reaching a healthy weight lower the chance of type 2 diabetes, and telling your doctor early in a future pregnancy means glucose can be checked from the start. [More on this: High-Risk Pregnancy](https://www.amalkehail.com/en/clinical-interests/high-risk-pregnancy/) ## When to seek urgent care If any of the following happens, call 998 for an ambulance or go to the nearest emergency department. - Your baby is moving less than you are used to, or the pattern of movements has changed. - If you take medicine for gestational diabetes: signs of low blood glucose, such as shaking, sweating or confusion, that do not improve after you treat them in the way you were shown. - Signs of pre-eclampsia: a severe headache, changes in vision such as flashing lights, pain under the ribs, or swelling of the face, hands or feet that comes on suddenly. [Ambulance **998**](tel:998) [Police **999**](tel:999) This page is general information. It does not replace a consultation or advice about your own situation. ## Sources - [NICE NG3: Diabetes in pregnancy (2015, updated)](https://www.nice.org.uk/guidance/ng3) - [NICE NG201: Antenatal care (2021)](https://www.nice.org.uk/guidance/ng201) - [NHS: Gestational diabetes, treatment](https://www.nhs.uk/conditions/gestational-diabetes/treatment/) - [NHS: Gestational diabetes](https://www.nhs.uk/conditions/gestational-diabetes/) ## Related reading - [Clinical interest High-Risk Pregnancy What a high-risk label means, why some pregnancies need closer care, and what extra monitoring and birth planning usually involve.](https://www.amalkehail.com/en/clinical-interests/high-risk-pregnancy/) - [Article Pre-eclampsia: what it is and the warning signs to know What pre-eclampsia is, who is more likely to have it, and the symptoms that need urgent care, in pregnancy and after birth.](https://www.amalkehail.com/en/articles/pre-eclampsia-warning-signs/) - [Article Morning sickness: what helps, and when it needs treatment When pregnancy sickness usually starts and eases, what can help, and the signs that mean it needs treatment the same day.](https://www.amalkehail.com/en/articles/morning-sickness/) - [Article Warning signs in pregnancy and after birth: when to seek urgent care The signs in pregnancy, in labour and after the birth that need urgent care, and what to do when you notice one.](https://www.amalkehail.com/en/articles/pregnancy-warning-signs/) Consults at ### Al Mousa Day Surgery Center Al Mousa Day Surgery Center L L C licensed by DHA · licence DHA-F-0002039 **Address:** Villa No. 36, Al Wasl Road, Jumeirah 1, Dubai **Dr Kehail’s consulting hours:** Saturday to Thursday 10:00–17:00 **Phone:** Appointments are arranged by Al Mousa Day Surgery Center: [+971 4 345 2999](tel:+97143452999) [Open in Google Maps](https://www.google.com/maps/place/Al+Moosa+Clinics+%26+Day+Surgery+Center+(Since+1978)+%D8%A7%D9%84%D9%85%D9%88%D8%B3%D9%89+%D9%84%D8%AC%D8%B1%D8%A7%D8%AD%D8%A7%D8%AA+%D8%A7%D9%84%D9%8A%D9%88%D9%85+%D8%A7%D9%84%D9%88%D8%A7%D8%AD%D8%AF%E2%80%AD/@25.235404,55.270382,15z/data=!4m6!3m5!1s0x3e5f42ff8c596917:0xdfd281f9857277b3!8m2!3d25.2354043!4d55.270382!16s%2Fg%2F1hc4qhl9v?hl=en) [Where Dr Kehail practises](https://www.amalkehail.com/en/clinic/) --- Dr Amal Kehail, Specialist Obstetrics and Gynecology — Obstetrics and Gynecology — Practises at Al Mousa Day Surgery Center L L C Practises at Medcare Women And Child Hospital Br Of Medcare Hospital ## Professional and licensing information **Name:** Amal Kehail **Address:** Villa No. 36, Al Wasl Road, Jumeirah 1, Dubai **Email:** [reception@almousamedical.ae](mailto:reception@almousamedical.ae) **Phone:** [+971 4 345 2999](tel:+97143452999) **Licensed title:** Specialist Obstetrics and Gynecology **Specialty:** Obstetrics and Gynecology **DHA licence:** Dubai Health Authority — 00243361-001 **DHA licence:** Dubai Health Authority — 00243361-003 **Practises at:** Al Mousa Day Surgery Center L L C **Licensed by:** Dubai Health Authority **Facility licence:** DHA-F-0002039 **Practises at:** Medcare Women And Child Hospital Br Of Medcare Hospital **Address:** Sheikh Zayed Road, beside Manara Services Centre, Al Safa 2, Dubai **Phone:** [800 633 2273](tel:8006332273) **Licensed by:** Dubai Health Authority **Facility licence:** DHA-F-0001703 [Legal notice](https://www.amalkehail.com/en/legal/)