How is gestational diabetes treated?

Photo of a woman holding a romper suit (PantherMedia / Mitar gavric)

Elevated blood sugar levels can usually be lowered enough by changing your diet. Special dietary counseling can help. But some women who have gestational diabetes have so much sugar in their blood for such a long time that they have to inject insulin.

In gestational diabetes (diabetes in pregnancy), women's blood sugar levels are temporarily higher than usual. This is usually not a reason for concern. But gestational diabetes can increase the risk of rare complications in pregnancy and during childbirth. It is diagnosed with the help of a special type of blood test known as a glucose tolerance test.

If you are diagnosed with gestational diabetes, your gynecologist may refer you to a diabetes specialist (a diabetologist) for further treatment.

What can you do yourself?

Women who have gestational diabetes are advised to change their diet and, in some cases, do more exercise too. It's best to discuss which exact measures would be most suitable for you in a special consultation.

To find out whether changing their diet and doing more exercise really helps, woman can measure their blood sugar levels several times a day over a few weeks.

The goal is to reach the following blood sugar levels:

  • Before breakfast: Less than 95 mg/dl (5.3 mmol/l)
  • One hour after starting a main meal: 140 mg/dl (7.8 mmol/l)
  • Two hours after starting a main meal: Less than 120 mg/dl (6.7 mmol/l)

The readings are noted in a diary and taken along to the doctor's appointment. If your blood sugar levels are generally okay, it might be enough to only measure them once or twice a day.

How should you change your diet?

Women can talk with their doctor or a dietary counselor about how to change their diet. The most suitable approach will be different for different women, depending on things like how much they weigh, how much exercise they generally get, and their diet. Women are typically advised to cut down on carbohydrates ("carbs") because these foods lead to a rapid increase in blood sugar levels. But it's important to make sure that you get enough fiber, fats and proteins in your diet.

Women with gestational diabetes are also advised to have three not-too-big main meals per day, as well as two to three smaller meals per day. If they are overweight or obese, they are also advised to limit the number of calories in their diet every day. This number of calories is determined individually for each woman. Pregnant women shouldn't go on strict diets because their bodies need enough calories during pregnancy.

Do dietary supplements help?

Dietary supplements containing myo-inositol are marketed for the treatment of gestational diabetes, among other health problems. There's currently a lack of reliable research on the benefits and harms of using myo-inositol to treat gestational diabetes. But there is some weak evidence that it can help to prevent it.

Vitamin D is also sometimes claimed to help. There is no evidence to support these claims, though.

Can exercise help too?

Another way to lower your blood sugar levels is by getting regular exercise. The most suitable type of exercise will depend on factors like how fit you are and how your pregnancy is going. It's a good idea to discuss the options with your gynecologist. Types of exercise such as brisk walking, cycling and swimming are usually appropriate. But things like martial arts and ball games are too strenuous or too risky for the unborn child.

Doing about 30 minutes of intense physical exercise on at least three days per week can already make a difference. It's quite easy to regularly integrate brisk walks into your everyday life, for instance by doing small grocery runs by foot if you don't have to buy much.

What role does medication play?

Persistently high blood sugar levels can usually only be lowered with insulin injections. Other diabetes medications (such as tablets) haven't been approved for use in pregnant women and aren't recommended for them either. Metformin is the only medication that can be used as an alternative to insulin in pregnant women – but only in certain cases. Studies have shown that it is about as effective as insulin in the treatment of gestational diabetes.

Insulin lowers the amount of sugar in your blood. You inject it under your skin every day. About 1 out of 4 women who have gestational diabetes inject insulin until their baby is born. They stop this treatment as soon as their contractions start, and generally don't need any insulin treatment after their child is born.

Does treatment help to prevent complications?

Treating gestational diabetes can help to lower the risk of certain complications.

Birth weight

Research has shown that treatment reduces the number of babies with a high birth weight (over 4,000 g):

  • Without treatment, about 16 out of 100 women have a baby with a high birth weight.
  • With treatment, about 7 out of 100 women have a baby with a high birth weight.

But there’s no reason to worry about a baby's health just because they are large or heavy at birth. Most large babies are born healthy. It can be more difficult to give birth to large babies, though.

Shoulder dystocia

Treatment can lower the risk of a certain birth complication called shoulder dystocia. This is where it takes longer for the baby’s shoulders to come out after the head has already come out. Sometimes the child gets stuck in the birth canal for a relatively short while, but in rare cases he or she may get stuck for longer. Midwives and doctors then have to react quickly in order to make sure the child gets enough oxygen.

Studies have shown that treatment for gestational diabetes lowers the risk of shoulder dystocia:

  • Without treatment, shoulder dystocia occurs in about 3 to 4 out of 100 births.
  • With treatment, it occurs in about 1 to 2 out of 100 births.

Shoulder dystocia often leads to small injuries in the child and sometimes in the mother too. These usually heal well, though, without any long-term physical consequences.

Other complications

A number of studies have looked into whether treating gestational diabetes can reduce the risk of pre-eclampsia. This was not found to be the case. Pre-eclampsia is a rare complication of pregnancy, associated with high blood pressure in the mother. Treatment for gestational diabetes didn't affect the likelihood of other complications either, such as serious injuries. It also didn't affect the number of Cesarean sections.

It's not clear whether treating gestational diabetes has any long-term health benefits for the mother and/or her child – for instance, whether it lowers the risk of developing type 2 diabetes.

Does the treatment have side effects?

Research in this area hasn't specifically looked into the possible disadvantages or harmful effects of treatment for gestational diabetes.

The treatment can involve a bit of effort. For instance, you have to prick your finger several times a day in order to measure your blood sugar levels. Some women find this unpleasant. Changing your diet also requires a bit of discipline. Being diagnosed with gestational diabetes can make women worry, too. This makes it all the more important to be aware that the vast majority of women with gestational diabetes give birth to healthy children.

What happens after the birth?

Newborn babies are regularly checked over in the first few days after the birth, to look for any problems. These include some that could be related to gestational diabetes, such as breathing problems or low blood sugar (hypoglycemia). The baby's blood sugar levels are already measured within the first few hours of birth. It's important to already feed the newborn about 30 minutes after they are born (breastfeed, if possible).

If the mother injected insulin or took metformin during the pregnancy, her blood sugar is measured regularly in the first few days after the birth. The blood sugar levels usually return to normal quite soon. If they remain high, she is referred to a diabetes specialist (diabetologist) for further treatment. If the mother only changed her diet (didn't use medication for diabetes) during the pregnancy, her blood sugar is generally no longer measured after the birth.

All women who have gestational diabetes are advised to talk with their doctor after the birth, to decide whether it's a good idea to do further tests or change their lifestyle. Many are advised to do a glucose tolerance test 6 to 12 weeks after the birth, in order to make sure that they haven't developed "normal" diabetes that needs to be treated.