Gestational Diabetes: Screening, Diet and Follow-Up

A fasting blood test, a glass of very sweet liquid, two hours of waiting at the lab, then the verdict: gestational diabetes. The word is worrying, especially as sokkar (diabetes, in Moroccan Darija) often brings to mind a relative on lifelong treatment. This kind of diabetes is different: it appears during pregnancy, responds well to treatment and usually goes away after the birth.

It is also common. In France it affected 16.4% of pregnant women in 2021, up from 10.8% in 2016, partly because doctors are looking for it more carefully, according to the French national health insurance (Assurance maladie). Here is how it is detected, what it changes on your plate, Moroccan cooking included, and why follow-up continues after the baby arrives.

What is gestational diabetes?

It is an excessive rise in the level of sugar in the blood (blood glucose) that appears during pregnancy. Pregnancy increases the need for insulin, the hormone that moves sugar into the cells. When the body cannot produce enough, sugar builds up in the blood. According to the UK’s NHS, it mainly occurs in the second and third trimesters.

It generally causes no symptoms: thirst, needing to pee often or tiredness are easily mistaken for common pregnancy discomforts. Everything therefore depends on screening.

Are you at higher risk?

Any pregnant woman can develop it, but the Assurance maladie lists several risk factors:

• being over 35;
• being overweight before pregnancy (body mass index of 25 or more);
• diabetes in your father, mother, brother or sister;
• gestational diabetes in a previous pregnancy, which comes back in 30 to 84% of cases according to studies;
• a previous baby weighing more than 4 kg at birth;
• polycystic ovary syndrome.

The NHS adds certain family backgrounds (South Asian, African, Caribbean, Middle Eastern) and a history of weight-loss surgery.

In Morocco, the Ministry of Health pays particular attention to pregnant women in diabetes screening, carried out in primary healthcare facilities, as well as to mothers who have previously had gestational diabetes or a baby weighing more than 4 kg (pharmacie.ma, 2017). Mention any such history at your very first appointment.

How does screening work?

It all comes down to blood tests. In France, all pregnant women also have their urine checked for sugar at every visit: if it is positive, blood glucose is tested.

In the first trimester, in France, a fasting blood glucose test is planned for women with at least one risk factor.

Between 24 and 28 weeks of pregnancy (counted from your last period), you have the oral glucose tolerance test (OGTT). After 8 to 10 hours of fasting, a blood sample is taken, then you drink a solution containing 75 g of glucose. Blood glucose is measured one hour and then two hours later. A single value at or above the thresholds is enough for a diagnosis:

Practices vary between countries. France and the UK target women at risk, whereas the Quebec programme offers the test to all pregnant women between 24 and 28 weeks. In Morocco, ask your doctor or midwife when to have the fasting glucose test and the OGTT, whether or not you have a risk factor. The other tests in your pregnancy care are summarised in our article on pregnancy scans and tests.

What are the risks for your baby and for you?

Well monitored, gestational diabetes does not usually prevent a normal pregnancy and birth: that is precisely what treatment is for. When blood sugar stays too high, the Assurance maladie and the NHS mainly describe:

• a larger-than-average baby (macrosomia, more than 4 kg at term), which can complicate the birth and make a caesarean more likely;
• low blood sugar in the newborn in the hours after birth;
• too much amniotic fluid and a higher risk of premature birth;
• high blood pressure or pre-eclampsia in the mother;
• newborn jaundice, which sometimes needs treatment.

The NHS also mentions a rare risk of the baby dying before birth. For the mother, the long-term risk of type 2 diabetes increases.

What should you eat with gestational diabetes?

Treatment almost always starts on your plate, ideally with a dietitian. This is not a weight-loss diet: Quebec authorities even advise against cutting out any food group, so that neither you nor your baby misses out on useful nutrients.

The principles come down to four rules:

1. Three meals and two snacks, at regular times, to spread carbohydrates across the day.
2. Slow-release carbohydrates at every meal, in suitable amounts: wholemeal or barley bread, lentils, chickpeas, beans.
3. Fibre and protein in the same meal (vegetables, egg, fish, meat, dairy): they help control blood sugar.
4. No big sources of sugar: fruit juice, fizzy drinks, cakes, ice cream, sugar added to coffee or milk.

Applied to the Moroccan table, these rules look roughly like this:

An insulated water bottle helps you choose water over sugary drinks, and an insulated lunch box lets you take your snack to work. The usual food safety rules of pregnancy still apply: see our guide to eating well when pregnant.

If Ramadan falls during your pregnancy, be aware that fasting is generally not advised with gestational diabetes: talk to your doctor before the month begins and read our article on fasting during Ramadan while pregnant or breastfeeding.

Physical activity, self-monitoring and insulin

Moving is part of the treatment. Unless there is a medical reason not to, the Assurance maladie advises about 30 minutes of activity, 3 to 5 times a week. Walking, swimming and prenatal yoga are good choices, according to the NHS. Ask your doctor before starting any new activity, and find ideas in our article on exercise during pregnancy.

You will also be given a blood glucose meter: you prick your fingertip when fasting and after meals, as often as your doctor advises. In France, the targets not to exceed are 0.95 g/l fasting, 1.30 to 1.40 g/l one hour after a meal, and 1.20 g/l two hours after.

If, after about ten days of adapted eating, your readings stay above these targets, treatment is added. In France this means insulin, prescribed in just over one in four cases of gestational diabetes; in the UK, tablets may also be offered. The treatment and its doses are a matter for your doctor alone.

Is the birth any different?

If the diabetes is well controlled, the birth usually goes ahead normally, sometimes after closer monitoring towards the end of pregnancy. The NHS recommends giving birth before 41 weeks, offering induction or a caesarean if needed. An earlier birth may be discussed if blood sugar is poorly controlled. A caesarean may also be considered if the baby is estimated at more than 4.2 kg, case by case and with your agreement.

After the birth: follow-up you should not skip

For your baby, blood sugar is monitored from birth. Your baby is fed as soon as possible, then every 2 to 3 hours, to limit swings in blood sugar. If you are breastfeeding, the first feeds meet this need: see our tips for getting breastfeeding off to a gentle start.

For you, gestational diabetes usually disappears with the birth, but it leaves a mark: according to the Assurance maladie, the risk of type 2 diabetes is seven times higher and lasts for at least 25 years. Hence this schedule:

• a first blood glucose check within three months of the birth, often at the postnatal visit (between 6 and 8 weeks in France, between 6 and 13 weeks in the UK);
• after that, a check every 1 to 3 years in France, every year in the UK;
• screening before any new pregnancy.

The ways to prevent it are well known: stay active, eat a balanced diet, do not smoke and, if needed, lose excess weight. When choosing contraception after the baby, mention this history.