Gestational Diabetes: Tests, Treatment & Delivery

Gestational diabetes is diabetes that appears for the first time in pregnancy, usually in the second half, because the placenta produces hormones that make the body's insulin work less well. In most women the pancreas compensates. In some it cannot, and the blood sugar rises.

It is common, it is manageable, and in the great majority of women it resolves after delivery. It is also one of the most confusingly explained diagnoses in Indian obstetrics, because two different testing protocols are in use here and they do not agree with each other.

This page covers all of it: which test you were given, what the numbers mean, what it does to the pregnancy and the baby, how it changes delivery, how it is treated, and the test after birth that matters more than any of them.

How common is it in India?

A meta-analysis pooling 110 Indian studies put the national prevalence at 13%. It varies substantially by region — around 16.1% in the north, where Gurugram sits, against 7% in the west — and is slightly higher in urban populations, 12% against 10% rural.

South Asian women develop gestational diabetes at lower body weights than European women, which is why the BMI threshold that triggers concern is lower here, and why "but I am not overweight" is not a reason to skip the test.

The part nobody explains: which test you were given

Two protocols are in common use in India, and they produce genuinely different answers. In that same meta-analysis, the pooled prevalence was 13% using DIPSI and 17% using the fasting IADPSG criteria — on comparable populations. A woman diagnosed in one clinic might not have been diagnosed in another.

This is not a scandal and it does not mean anyone is wrong. It means the thresholds are drawn at different points on a continuous curve, and knowing where yours was drawn helps you understand your result.

If you take one thing from this section: ask which protocol was used and what your actual numbers were. "Your sugar test was positive" is not enough information to act on for the next five months.

How the DIPSI test is actually done

This is the test used at this clinic, and it is the one that causes the most confusion at the lab — mostly because women are told to come fasting when they should not be. You come without fasting, you drink 75 g of glucose dissolved in about 300 ml of water within five minutes, you stay seated, and one blood sample is taken exactly two hours later. That is the whole test.

Above 140 mg/dL at that two-hour sample is gestational diabetes. There is no second confirmatory test to wait for, which is one of the practical advantages of doing it this way.

If you are having the fasting OGTT instead

Some centres use the fasting 75 g test. It is the one people get wrong, and a badly prepared test produces a result nobody can interpret:

• Eat normally for three days beforehand — at least 150 g of carbohydrate a day. Cutting carbohydrates before the test to "pass" it does not work; it distorts the result and can make it falsely abnormal.
• Fast for 10 to 16 hours overnight. Water is allowed.
• Go in the morning, usually between 7 and 9 a.m.
• Stay seated for the whole test. Walking about, climbing stairs or going home in between changes the numbers.
• Do not smoke and do not eat anything until the last sample is taken.
• Allow two to three hours. Take something to read.

For the DIPSI test none of the fasting rules apply — but the three-days-of-normal-eating rule still does, and you still need to stay seated for the two hours.

If you vomit the drink, tell the person doing the test. The result will not be valid and it needs rescheduling rather than reporting.

When should you be tested?

• Every pregnant woman, at 24 to 28 weeks. This is the standard screening window.
• At the first antenatal visit as well, if you have risk factors — and if that early test is normal, it is repeated at 24 to 28 weeks anyway.
• A raised sugar found before 20 weeks is more likely to be pre-existing type 2 diabetes that nobody had diagnosed, and is managed differently.

What it does to the pregnancy

The honest framing is that gestational diabetes is a risk multiplier, not a sentence. Well-controlled, most of these risks fall close to background. Uncontrolled, they are real.

For you

• Pre-eclampsia. Treating gestational diabetes reduces it from around 18% to 12% — one of the clearest demonstrations that the treatment does something.
• Polyhydramnios, too much fluid around the baby, which brings its own risks of preterm labour and cord prolapse.
• A higher chance of caesarean, mostly driven by the baby's size rather than by the diagnosis itself.
• Infections, particularly urinary and thrush, which are more frequent when sugars run high.

For the baby

The mechanism is worth understanding, because it explains everything else. Glucose crosses the placenta; insulin does not. So the baby receives your excess sugar, makes its own insulin to deal with it, and that insulin acts as a growth hormone.

• Macrosomia — a large baby, with fat deposited disproportionately around the shoulders and chest.
• Shoulder dystocia, where the shoulders become stuck after the head delivers. It is the complication that drives most of the caution about size.
• Low blood sugar in the first hours after birth, because the baby's insulin production is still running high once your supply stops. This is why babies are heel-pricked after delivery and fed early.
• Jaundice, polycythaemia and low calcium in the newborn period.
• Respiratory distress, as lung maturity can lag.
• A higher risk of stillbirth where control is poor — the reason for extra monitoring and for not going far past the due date.

One important reassurance: gestational diabetes appears after the baby's organs have formed, so it does not cause birth defects. That risk belongs to diabetes that was present before conception and poorly controlled at the time, which is a different condition and a reason for preconception planning if you already have diabetes.

The sugar targets

Bring the logbook to every appointment. The pattern matters far more than any single reading: a fasting value that keeps creeping up points to a different treatment from post-meal spikes.

Treatment, in the order it is tried

1. Diet

This is the treatment for most women, and it is genuinely effective. The principles:

• Three modest meals and two to three snacks spread through the day, rather than two large meals.
• Fewer carbohydrates at breakfast than at other meals — insulin resistance is highest in the morning, which is why the same paratha behaves differently at 8 a.m. and at 8 p.m.
• Whole grains over refined, and carbohydrate always paired with protein or fat rather than eaten alone.
• A bedtime snack, which prevents the overnight ketosis that a long fasting gap can cause.
• Not a starvation diet. Cutting food drastically produces ketones, which are not good for the baby. The aim is redistribution, not deprivation.

Our guide to foods in pregnancy covers the general list; the gestational diabetes version is about timing and pairing as much as about what is on the plate.

2. Exercise

Underused and genuinely powerful. The target is about 150 minutes of moderate activity a week, roughly 30 minutes on five days.

The single most useful version is a 20 to 30 minute walk after meals. Muscle takes up glucose without needing insulin, so a post-meal walk lowers the very reading that is most often abnormal, and the effect lasts for around three hours. A great many women avoid tablets entirely by adding this one habit.

3. Medication

Started when diet and activity have not reached target after one to two weeks, or immediately if the numbers at diagnosis are high.

What starting insulin actually involves

The fear of insulin in India is out of all proportion to the reality, and it costs women good control. What it actually means:

• A very fine needle into the fat of the abdomen or thigh, using a pen. Most women describe it as less painful than the finger prick used to test the sugar.
• Often just one injection at bedtime if the problem is only the fasting reading. Where post-meal values are also high, a rapid-acting insulin is added before meals.
• Doses are calculated from your weight and the stage of pregnancy, then adjusted from your logbook. They will rise through the pregnancy, because insulin resistance rises as the placenta grows. That is expected, not a sign of failure.
• It stops at delivery in almost all women with gestational diabetes.
• Needing insulin does not mean you did badly. It reflects how much the placenta is interfering, which is not something willpower changes.

The extra tests and appointments

Scans are arranged by referral. Consultation, blood tests and glucose testing are done at the clinic.

How it changes delivery

This is the section women want most and get least, so here it is plainly.

Timing

• Diet-controlled, sugars at target, baby growing normally: there is no reason to deliver early. Pregnancy can continue to around 40 to 41 weeks, managed much like any other.
• Controlled on medication: delivery is generally planned at 39 weeks.
• Poorly controlled, or with other complications: earlier, usually 37 to 38 weeks, weighing the risks of continuing against those of prematurity.

Vaginal or caesarean?

Gestational diabetes is not in itself an indication for a caesarean. Most women with well-controlled sugars and a normally grown baby are induced or labour spontaneously and deliver vaginally.

What shifts the discussion is size. Where the estimated fetal weight is 4.5 kg or more in a diabetic pregnancy, a planned caesarean is discussed, because of the risk of shoulder dystocia. Below that, the usual obstetric considerations apply.

One honest caveat that is rarely mentioned: ultrasound estimates of fetal weight are not precise, particularly at the top of the range, where they can be out by 10% or more in either direction. A scan estimate is one input into the conversation, not a verdict, and it is reasonable to ask how confident the estimate is.

During labour

• Blood sugar is checked regularly through labour, usually hourly, and kept in a narrow range.
• An insulin and dextrose infusion may be used if you were on insulin or if the sugars drift.
• Continuous fetal monitoring is usual.
• The paediatric team is informed, and the baby's blood sugar is checked in the first hours.
• Early feeding is encouraged, within the first hour where possible, to prevent the newborn dip.

After the birth

In almost all women the diabetes disappears within hours of the placenta being delivered, and insulin or metformin is stopped immediately. Sugars are usually checked once or twice in the first two to three days to confirm.

Breastfeed if you can. It reduces the mother's later risk of type 2 diabetes and helps stabilise the baby's blood sugar, and it is one of the few things in this whole subject that is both free and unambiguously beneficial.

What it means for your future

Gestational diabetes is one of the strongest early warnings of type 2 diabetes that exists. Reported rates of later diabetes range widely — from around 15% to 70% depending on the population and how long they were followed — with roughly a sevenfold increase in risk compared with women who did not have it.

Written like that it sounds like a sentence. It is closer to the opposite, because this is a risk that responds to action better than almost any other:

• Early lifestyle intervention reduces progression to type 2 diabetes over ten years by 35 to 40%.
• Even a modest reduction in BMI lowers the risk by around 25%.
• The recurrence risk in a future pregnancy is substantial, which is a reason to be tested early next time rather than a reason to avoid pregnancy.

For the child, there is a modestly raised long-term risk of obesity and glucose problems, which is influenced by feeding, activity and family habits over years — not fixed at birth.

Managing this in Gurugram

What matters practically: knowing which protocol your test used and what the numbers were; a diet plan built around what you actually eat rather than a printed sheet; the post-meal walk; a logbook reviewed properly at each visit; growth scans arranged on time; and a delivery plan made in advance rather than in the last week.

Consultation, blood tests and glucose tolerance testing are done at the clinic. Scans are arranged by referral. Delivery is at hospital.

And the appointment six weeks after the birth, for the OGTT, is booked before you leave — because that is the one that decides the next thirty years rather than the next three months.

Where to see us

Dr. Anam's Women Health Clinic, Sector 51 (Mayfield Garden) and Sector 56, Gurugram. Open seven days a week, including Sundays.

The bottom line

Ask which test you had and what the number was, because the protocol chosen genuinely changes who gets diagnosed. Here it is the DIPSI test: one non-fasting sample at two hours, and above 140 mg/dL is a diagnosis. Most women reach target on diet and a walk after meals. If you need insulin, it does not reach your baby, and needing it is not a failure. It is not an automatic caesarean, and most well-controlled women deliver vaginally.

And book the test six weeks after delivery before you go home. Half of women never have it, and it is the one that tells you what happens next in your own life.