Gestational Diabetes in Pregnancy (GDM): Screening, Diet and Care
A diagnosis of gestational diabetes can feel worrying, but it is one of the most common and most manageable conditions in pregnancy. With the right monitoring and a few adjustments, the great majority of women go on to have a healthy baby and a straightforward birth. This guide explains what GDM is, how it is tested for, and how it is looked after.
Medically reviewed by Dr. Priyadatt Patel, MBBS, MS (Obstetrics & Gynaecology) — Senior Gynecologist · Advanced Laparoscopic Surgeon · IVF and Endometriosis Programme Lead & High-Risk Obstetrics, Balaji Horizon Women’s Hospital, Ahmedabad. · Last reviewed: 3 July 2026.
Gestational diabetes mellitus (GDM) means higher-than-normal blood sugar that is first recognised during pregnancy. It is very common, and Indian women are known to be among those at higher risk, so being diagnosed does not mean anything is wrong with you or that you have done something to cause it. It is simply the way some bodies respond to the natural hormonal changes of pregnancy. The reason we screen for it, and treat it when it is present, is straightforward: good blood-sugar control keeps both mother and baby well, and the outcomes for well-managed GDM are usually excellent. For the wider picture of pregnancy care, see our pregnancy care, antenatal care and high-risk pregnancy pages.
What is gestational diabetes?
During pregnancy, the placenta produces hormones that make the body’s cells less responsive to insulin, the hormone that moves sugar from the blood into the cells for energy. This “insulin resistance” is normal and helps direct nutrients to the growing baby. Usually the mother’s pancreas simply makes more insulin to compensate. In gestational diabetes, the pancreas cannot quite keep up with the extra demand, so blood-sugar levels rise. GDM is different from pre-existing type 1 or type 2 diabetes: it appears during pregnancy, most often in the second or third trimester, and in most women it settles again after the baby is born.
Why gestational diabetes matters
It helps to be honest and balanced here. When blood sugar is kept within target, most pregnancies affected by GDM proceed normally and babies are born healthy. The reason control matters is that persistently high blood sugar crosses the placenta and prompts the baby to grow larger than average (macrosomia), which can make birth more difficult, increase the chance of a difficult shoulder delivery, and raise the likelihood of a caesarean. It can also cause excess amniotic fluid, and babies can have a low blood-sugar dip in the first hours after birth. For the mother, GDM slightly raises the risk of high blood pressure and pre-eclampsia. None of this is meant to frighten you, it is precisely why screening and treatment exist. With good control, the risks fall substantially and outcomes come close to those of pregnancies without GDM.
Who is at higher risk?
Some women are more likely to develop GDM, including those who are overweight, have a family history of diabetes, have had gestational diabetes or a large baby in a previous pregnancy, have polycystic ovary syndrome (PCOS), are older, or are of South Asian ethnicity. However, a great many women who develop GDM have none of these risk factors. Because risk factors alone miss too many cases, screening in India is generally offered to all pregnant women rather than only those thought to be at risk.
How and when is GDM screened for?
Screening is usually done between 24 and 28 weeks of pregnancy, and earlier, often at the first booking visit, for women at higher risk. The test is an oral glucose tolerance test (OGTT): you drink a measured glucose solution and your blood sugar is checked afterwards. In India, a widely used and practical approach is the single-step DIPSI test, in which a 75 g glucose drink is given regardless of when you last ate and blood sugar is measured two hours later, with a value of 140 mg/dL or more indicating GDM. Internationally, a fasting 75 g OGTT with measurements at fasting, one hour and two hours (the IADPSG/WHO approach) is also used. The exact protocol varies between clinics; what matters is that you are screened and the result interpreted correctly. We tailor the timing to your individual risk.
Understanding your blood-sugar numbers
If GDM is diagnosed, treatment is guided by target blood-sugar levels. Commonly used targets are a fasting level below about 95 mg/dL (5.3 mmol/L), below about 140 mg/dL (7.8 mmol/L) one hour after a meal, and below about 120 mg/dL (6.7 mmol/L) two hours after a meal. “Fasting” means first thing in the morning before eating; “post-meal” readings show how your body handles the food you eat. Your own targets will be confirmed by your care team, and the aim is steady, in-range numbers rather than perfection at every single reading.
Diet, the foundation of treatment
For most women, careful eating is the first and most powerful treatment, and it is often enough on its own. The principles are simple: keep carbohydrate portions consistent and moderate, choose slower-releasing complex carbohydrates (whole grains, millets, legumes and plenty of vegetables) over refined flour, sugar and sweets, and always pair carbohydrates with protein and fibre to blunt the rise in blood sugar. Spreading food across three modest meals and two to three small snacks, rather than a few large meals, keeps levels smoother, and it helps not to skip breakfast. In an everyday Indian diet this often means portion-controlling rice and roti, favouring whole grains and millets, filling half the plate with vegetables and dal, and being cautious with fruit juices and sweets. Importantly, this is not about starving yourself, your baby needs good nutrition, but about the quality and timing of what you eat. A dietitian can help build a plan that fits your routine and preferences.
Physical activity
Regular, moderate activity lowers blood sugar by helping the muscles use glucose, and it improves the body’s sensitivity to insulin. A brisk walk of around 20 to 30 minutes, particularly after meals, is one of the most effective and accessible ways to reduce post-meal readings. For most pregnancies this is safe and beneficial, but it is always worth confirming with your doctor, especially if you have any pregnancy complication.
Monitoring your blood sugar at home
Most women with GDM are asked to check their own blood sugar with a small home glucometer, typically a fasting reading in the morning and readings after meals, as advised. Keeping a simple log turns the targets into something real and practical: it shows which meals suit you, whether diet and activity are keeping you in range, and whether additional treatment might be needed. It also gives you a sense of control, which many women find reassuring.
When medication or insulin is needed
If diet and activity do not bring blood sugar to target, which happens for a meaningful minority of women, medication is added. This is not a failure of effort or willpower; it simply reflects how your body is responding to pregnancy hormones. Insulin is the preferred treatment when medication is required: it is highly effective, the dose can be adjusted precisely, and it does not cross the placenta to the baby. Metformin, a tablet, is sometimes used as well and is a reasonable option in some situations, though it does cross the placenta and its long-term data in children are still maturing, so the choice is made individually with you. Insulin injections understandably sound daunting at first, but they are well tolerated, and our team will teach you exactly how and when to use them.
Keeping an eye on the baby
Because GDM can affect the baby’s growth and the amount of amniotic fluid, you will usually have extra antenatal checks and ultrasound growth scans, particularly in the third trimester. Additional fetal monitoring may be advised if you are on medication or if blood sugar has been difficult to control. These checks let us confirm the baby is growing well and plan the safest timing and mode of birth.
Labour, birth and timing
A common worry is that gestational diabetes automatically means a caesarean. It does not. Many women with well-controlled GDM have a normal vaginal birth. The timing of delivery is decided individually, often planned somewhere around 38 to 40 weeks depending on how well blood sugar is controlled and how the baby is growing, and sometimes a little earlier if there are concerns. During labour your blood sugar is kept in range, and after birth the baby’s blood sugar is checked, as newborns of mothers with GDM can occasionally have a temporary low dip that is easily managed.
After the birth, and your future health
In most women, blood sugar returns to normal soon after delivery, and gestational diabetes resolves. A follow-up glucose test around 6 to 12 weeks after birth is recommended to confirm this. It is important to know that having had GDM does raise your lifetime risk of developing type 2 diabetes, studies suggest up to half of women may do so within one to two decades. Rather than a source of anxiety, this is best seen as valuable early warning: maintaining a healthy weight, eating well, staying active and having periodic blood-sugar checks substantially lowers that risk. You are also more likely to develop GDM again in a future pregnancy, so earlier screening will be arranged next time. Breastfeeding is beneficial for both you and your baby, including for your own metabolic health.
Frequently Asked Questions
Will gestational diabetes harm my baby?
Does GDM mean I will need a caesarean?
Can I control gestational diabetes with diet alone?
Is insulin safe in pregnancy?
Will the diabetes go away after delivery?
Does having GDM mean I will get diabetes later in life?
This article is for general education and does not replace personalised medical advice. Blood-sugar targets, medication and the timing of birth should always be decided with your own obstetrician, who knows your full history. If you have been diagnosed with gestational diabetes, please follow the plan agreed with your care team.
Expecting, or diagnosed with gestational diabetes?
Balaji Horizon Women’s Hospital provides structured antenatal and high-risk pregnancy care in Ahmedabad, including gestational-diabetes screening, dietary guidance, blood-sugar monitoring and growth surveillance. To arrange a consultation, call or WhatsApp +91 99094 96027 (hospital +91 97234 31544) or visit our contact page.
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