Gestational Diabetes 101: Symptoms, Causes & Treatment

Gestational diabetes, also known as pregnancy diabetes, is a condition that can have long-term effects on both baby’s and mother’s health.

Learn the symptoms, causes & effects of gestational diabetes and how to prevent it.

What is Diabetes?

Diabetes Mellitus happens when someone has a problem with insulin production, or their body does not respond well to insulin. 

The Role of Insulin

To explain why diabetes takes place, we must understand the role of insulin, a hormone produced by our pancreas.

Insulin is the hormone that controls how well cells are able to receive energy – in the form of glucose – from the blood. 

After our body breaks down the carbohydrates in the food, the sugars or glucose from it do not directly enter our cells where we can use them for energy. What happens is that they just float in the blood until insulin enables them to enter our cells, where we can then turn this glucose into energy or store them. Essentially, our cells are locked, and insulin acts as the key to open them up for glucose.

Insulin Issues that Lead to Diabetes

Diabetes occurs when we have insulin issues. This usually happens in two ways:

1. The pancreas is not producing enough insulin, or not producing insulin at all, or
2. Our body no longer recognises insulin

Lack of insulin usually happens in people with type 1 diabetes, while insulin resistance develops later in life and is classified as type 2 diabetes.

Regardless of the type of diabetes, the result of insulin issues is the same: the glucose or sugar cannot enter our cells, and so, they stay afloat in the blood, causing high blood glucose or hyperglycemia. Both high blood sugar and reduced energy production can cause problems.

What is Gestational Diabetes?

Gestational Diabetes Mellitus (GDM) refers to diabetes that develops during pregnancy. 

GDM is more common in the second or first trimester, and nearly always resolves quickly after birth. Globally, around one in six pregnant women develops GDM.

Anyone who has had GDM has a much higher risk of developing type 2 diabetes mellitus (T2DM) later in life.

What Causes Gestational Diabetes?

A growing foetus and all of the other changes that go along with pregnancy put extra demands on the body. Normally, the body is able to compensate for these extra demands, but sometimes it does not make enough insulin to meet the changing needs. This results in gestational diabetes.

Another cause of gestational diabetes may be reduced insulin sensitivity. This means that the body does not respond to insulin the usual way and is less effective at getting the sugar from the bloodstream into the cells. This occurs as the hormones produced during pregnancy can affect a mother’s metabolism.

Risk Factors of Gestational Diabetes

The exact causes of gestational diabetes are not entirely clear, but we do know that some people are more at risk of developing gestational diabetes than others. Some risk factors of gestational diabetes include:

• Being over the age of 35
• Being overweight or obese
• A close family history of diabetes or gestational diabetes
• Having had gestational diabetes in a previous pregnancy
• Ethnicity: the risk of developing GD varies depending on your ethnic background, and South Asian women seem to be at the highest risk of developing GD.

Assessing a person’s risk of developing gestational diabetes should begin early in pregnancy and continue throughout. Routine prenatal assessments in Singapore include a screening test for GDM for all pregnant women at around 24 to 28 weeks of pregnancy.

Gestational Diabetes Symptoms

Having gestational diabetes does not necessarily cause any specific symptoms, and is often only picked up at a routine prenatal appointment. 

That being said, having high blood sugar levels can cause some symptoms, which may include:

• Fatigue
• Extreme thirst
• Passing more urine than usual

However, these symptoms are fairly common in pregnancy with or without gestational diabetes, so it is not always easy to tell them apart.

Effects of Gestational Diabetes on Mothers

Besides an increased risk of developing type 2 diabetes later in life, gestational diabetes makes people more prone to developing fungal infections like thrush (candida) and urinary tract infections. Regardless of whether these infections are caused by gestational diabetes, it is important to treat them quickly in pregnancy.

Furthermore, gestational diabetes is also associated with having high blood pressure in pregnancy. Blood pressure is routinely monitored at prenatal appointments, so problems should be picked up quickly. Untreated high blood pressure (hypertension) in pregnancy can lead to a condition called preeclampsia, which can have serious consequences.

Gestational Diabetes Test

Prenatal care incorporates a number of routine assessments during pregnancy. A mother’s risk of gestational diabetes will be considered, and routine blood tests, blood pressure and other vital signs will be regularly measured. 

A random blood glucose test, which can be done just by pricking a finger, measures blood sugar and gives us an idea of how well the body is producing insulin.

Anyone at high risk of gestational diabetes will need to have an oral glucose tolerance test (OGTT). This will involve fasting for around 8 hours – this means no food or drinks other than plain water – and then going for a blood test. After this initial blood test, they will have to drink a sugary drink that contains a measured amount of glucose. Blood tests will be repeated at several intervals after the glucose drink, which will show what the blood sugar levels are and whether the body is doing a good job of controlling insulin production.

Gestational Diabetes Diet

Like with other forms of type 2 diabetes, gestational diabetes responds well to a healthy diet and lifestyle. 

Mothers with gestational diabetes may be recommended to follow a low glycaemic index diet. This diet focuses on complex carbohydrates (i.e. starchy foods and wholegrains) which release energy slowly instead of simple carbohydrates (i.e. sugary and processed foods) which can cause blood sugar to rise and fall too quickly. Lots of vegetables, fruit, complex carbs and lean proteins make an ideal healthy diet for almost anyone but is especially important for individuals with diabetes.

Eating regular meals is key for people with fluctuating blood sugar levels. Skipping meals can cause more problems and may actually be dangerous for people on certain diabetic medications or insulin.

Treatment for Gestational Diabetes

For individuals with gestational diabetes, monitoring vital signs closely and keeping blood sugar at normal levels – the levels recommended by the healthcare team – can help prevent serious complications. 

For some, gestational diabetes can be managed with a healthy diet and lifestyle changes, but for others, medication needs to be introduced to help balance insulin and blood sugar levels.

Doctors are cautious about which medications they prescribe to pregnant or breastfeeding women, and any risks are carefully considered. Usually, one of the first medicines recommended to control blood sugar for gestational diabetes is metformin. Metformin has proven to show good results and has been used safely for gestational diabetes both in trials and in practice for many years.

Insulin may be required if the blood sugar level does not respond well to other treatments. Insulin is given as a subcutaneous injection, meaning it has to be injected into the layer of fat just under the skin. Most people are able to independently manage this at home, but you can also engage a home nurse to perform the procedure.

People who take insulin have to measure their blood sugar regularly, usually several times a day. It is important to learn to adjust the insulin dose depending on the blood sugar levels and the food they eat. Each person’s insulin dose is different and there are different regimes for taking insulin. Your doctor and healthcare team should develop a personalised plan tailored to your individual needs.

The insulin used is very similar to the kind naturally produced by the body, so you do not have to worry about any negative effect it may have on the pregnancy.