Gestational diabetes: causes, symptoms and treatment

Women with gestational diabetes (also known as gestational diabetes mellitus) have high blood sugar levels during pregnancy, often first occurring in the second trimester. It commonly also affects non-diabetics. The percentage of gestational diabetes cases is between 5% and 10%, meaning that for every 100 pregnant women, 5 to 10 are affected. This makes gestational diabetes one of the most common pregnancy complications. 

Gestational diabetes can generally be managed well with the right treatment. Many women’s blood sugar levels return to normal again after giving birth. Early diagnosis and an adapted lifestyle help to minimise any potential risks.

How exactly does gestational diabetes develop? The body releases more glucose (sugar) during pregnancy, since it requires more energy. At the same time, the pancreas produces more insulin in order to reduce the concentration of sugar in the blood. In some pregnant women, the pancreas is unable to handle the extra load, which causes an insulin deficiency. However, some women’s pancreas increases insulin production but their cells do not react to this stimulus. In this case, their blood sugar levels also don’t fall. Various factors increase the risk of getting gestational diabetes. These are:

• Being overweight
• Poor diet
• Diabetes mellitus in the family
• Gestational diabetes in previous pregnancies
• Being over 30 years of age
• A history of multiple miscarriages
• Taking cortisone preparations or medication to lower blood pressure
• Illnesses that are associated with insulin resistance (e.g. PCOS)

When it comes to gestational diabetes, the typical signs of diabetes often occur in a mild form, if at all. If blood sugar rises sharply, gestational diabetes can cause fatigue and weakness. There are also other possible gestational diabetes symptoms that the mother may notice:

• Inflammation of the vagina
• Urinary tract infections
• High blood pressure

Did you know? In most cases, those affected by gestational diabetes do not notice any symptoms. And although gestational diabetes doesn’t cause the baby to experience any symptoms, there are some potential adverse outcomes for the mother and unborn child.

Untreated gestational diabetes has some potential adverse outcomes for the mother and child. Possible complications for the mother are:

• Preeclampsia: formerly known as “toxaemia”. Those affected have water retention in their tissue and protein in their urine, as well as high blood pressure. Preeclampsia is a precursor to eclampsia and HELLP syndrome.
• Eclampsia: in some cases, gestational diabetes is accompanied by headaches and other neurological symptoms such as eye flashes. This may be indicative of eclampsia, which is life-threatening and requires medical treatment as soon as possible.
• HELLP syndrome: if you have gestational diabetes and notice symptoms such as nausea or vomiting, you may be affected by HELLP syndrome. Severe pain in the upper abdomen is also often caused by this. The syndrome develops within about an hour, and possible adverse outcomes include brain haemorrhage and multiple organ dysfunction syndrome, both of which are life-threatening.
• Premature delivery or miscarriage: sometimes a baby might be born prematurely if the mother has gestational diabetes, and miscarriages also occur occasionally. This is because mothers with gestational diabetes are more susceptible to infections and have more amniotic fluid.
• Birth complications: complications and injuries during birth are more common as a result of gestational diabetes. This is because the babies of mothers with gestational diabetes are often bigger. Experts usually recommend a caesarean section in these cases. 

In addition, gestational diabetes can have various effects on the child:

• Macrosomia: if the mother has gestational diabetes and high blood sugar levels, it’s likely that the baby has excess insulin and is growing at an above-average rate as a result. Babies considered larger than average have a birth weight of over four kilos. Despite their size and weight, babies of mothers with gestational diabetes are at risk of not developing fully. Babies affected by this often have breathing problems or clotting disorders.
• Malformations: if gestational diabetes occurs in the first trimester, the risk of malformations in the unborn child increases.
  

Gestational diabetes: long-term impacts for mother and child

Around 40% of women who have had gestational diabetes in a previous pregnancy develop gestational diabetes again in subsequent pregnancies. In addition, 25% to 50% of women who have suffered from gestational diabetes develop type 2 diabetes within 5 to 10 years. The children of these women also have an increased risk of becoming overweight and developing high blood pressure and diabetes, all of which are risk factors for cardiovascular disease.

Between the 24th and 28th week of pregnancy, doctors carry out a major gestational diabetes test. The first step is to determine the mother’s fasting blood sugar level. The oral glucose tolerance test during pregnancy involves drinking a glucose solution on an empty stomach within a few minutes. After an hour, the doctor takes a blood sample and measures her blood sugar levels again. If these are elevated, another test follows. The healthcare professional will check her blood sugar levels after another hour has passed, which is two hours after determining the fasting level.

What are the blood glucose levels of those affected by gestational diabetes? With gestational diabetes, at least one of the following levels is elevated:

• Cut-off level for fasting blood sugar: 5.1 mmol/L
• Cut-off level for blood sugar after one hour: 10 mmol/L
• Cut-off value for blood sugar after two hours: 8.5 mmol/L

Please note: you should not eat anything after 10 pm the day before having an oral blood glucose test during pregnancy. Also avoid drinking sweetened drinks and fruit juices, but opt for still water instead. Do not do any exercise either. All of this influences blood glucose levels and may make it difficult to correctly diagnose gestational diabetes.

Both mild and severe gestational diabetes must be treated. Sometimes all that is required is a change of diet. Some people, however, will need to take insulin. If your gynaecologist has diagnosed you with gestational diabetes, they will refer you to a diabetologist. You will discuss the next steps for managing gestational diabetes with this specialist. Women with gestational diabetes generally learn how to measure their blood sugar levels themselves. In the first one to two weeks after their diagnosis, they measure it four times a day: the fasting level in the morning and then one to two hours after each main meal. After this, one measurement per day is often sufficient.

Gestational diabetes: what can you eat? 

The primary focus during pregnancy is your nutrition. You should eat less fat and more protein. Generally, you should reduce your carbohydrate intake, and eat higher-value carbohydrates. Gestational diabetes is usually easy to manage with a balanced diet. 

But what does an optimal diet look like when it comes to gestational diabetes? Experts recommend the following daily macro split for those affected:

• 40% to 50% carbohydrates: opt for wholegrain products if you can. Foods made from white flour cause blood sugar levels to rise sharply.
• 30% to 35% fats: if you have gestational diabetes, eat foods that contain vegetable fats and oils.
• 20% protein: choose low-fat milk or dairy products, for example. It’s also a good idea to eat low-fat meat such as poultry.
• At least 30 grams of fibre: this is found in wholegrain products and pulses, among other things. 

A nutrition plan is particularly important for those who have gestational diabetes. This makes it easier when adjusting their diet. Below is an example of such a plan:

It’s better to eat several small meals rather than fewer large ones in order to avoid spiking your blood sugar levels. You should also cut down on sugary drinks and sweets; zero-sugar and diet drinks are okay from time to time. Always follow the recommendations of your diabetologist. Dietary changes, such as the Louwen diet, that are not designed for gestational diabetes are best discussed with a medical professional in advance. 

Exercising with gestational diabetes

Also make sure to get enough exercise on a daily basis. What do you need to consider in this respect if you have gestational diabetes? Engage in 30 minutes of moderate exercise at least three times a week. Gentle movement during pregnancy, such as swimming or specific courses for expectant mothers, is a great option. Getting enough exercise is important because it may help your cells to absorb insulin better and break down glucose more effectively.

Gestational diabetes: at what point do you need to start taking insulin?

You and your doctor will measure your blood sugar levels regularly. If they are constantly too high despite a healthy diet and exercise, treatment with insulin is required. People with gestational diabetes who require insulin can inject it themselves. For some women, one injection in the evening is sufficient, while others might need insulin once in the morning and once in the evening. The injected insulin works over a longer period of time (long-acting insulin). Women with gestational diabetes often also inject themselves with short-acting insulin before each meal. Your diabetologist will advise you on the right dose of insulin for your individual case of gestational diabetes. 

After the birth: gestational diabetes check-up

In most cases, gestational diabetes disappears on its own shortly after birth. To be on the safe side, however, your doctor will carry out another blood sugar test around six weeks after your baby is born. After that, a yearly check is sufficient. The risk of developing type 2 diabetes is still higher for years after having gestational diabetes.

After the birth, a specialist will check your child’s blood sugar levels regularly. Proper nutrition is very important for your child’s metabolism to adapt. Your midwife, nursing staff and lactation consultants will be happy to advise you on this topic.

By the way, pregnant women with diabetes can express their first milk (colostrum) shortly before giving birth and then freeze it. Give this to your child after birth if necessary.

It is not yet clear whether and how gestational diabetes can be prevented. However, experts recommend that women who are overweight lose weight. This helps them to reduce their risk of developing gestational diabetes. Weight loss can be achieved, for example, by changing your diet and moving more.

Gestational diabetes is no reason to panic. A pregnancy with well-managed gestational diabetes usually proceeds without any problems. Take all medical check­ups seriously and consult your doctor if you are unsure about anything.