Managing Gestational Diabetes

Gestational diabetes mellitus (also known as gestational diabetes or GDM) is a type of diabetes that only occurs during pregnancy. In many cases of gestational diabetes can be managed very well with nutritional support.

What is gestational diabetes?

Gestational diabetes mellitus is a type of diabetes that only occurs during pregnancy and affects 5-10% of pregnant people in Australia. Typically gestational diabetes will develop in the second or third trimester of pregnancy due to increased insulin resistance caused by hormones released by the placenta. Although there are some situations where it can occur earlier. You can have a great diet and still develop gestational diabetes! Some factors increase your risk of developing gestational diabetes, this includes:

Having a BMI over 25
Low levels of physical activity
A family history of diabetes
Prior history of gestational diabetes or having children with a high birth weight
Having PCOS

Gestational diabetes is divided into two categories: A1GDM which is responsive to nutritional therapy and can be diet controlled, and A2GDM which requires medication such as insulin.

Does vitamin D impact gestational diabetes?

A systematic review released in 2018 found low blood vitamin D levels could increase the risk of gestational diabetes. Vitamin D impacts gestational diabetes due to vitamin D improving insulin secretion, which helps to counteract the insulin resistance caused by pregnancy hormones. Therefore, having optimal levels of vitamin D before and early in pregnancy can help to prevent gestational diabetes, and there is some research that supports vitamin Dsupplementation to manage gestational diabetes.

In Australia 23% of adults are vitamin D deficient according to the latest Australian Health Survey. The reference range this is determined with is where a person is deemed deficient in vitamin D if they have less than 50 nmol/L of vitamin D in their blood. The issue with this is the reference range used comes from the average of the population and isn’t reflective of what is optimal for a person during pregnancy. Ideally in early pregnancy vitamin D levels are greater than 80 nmol/L but closer to 100 nmol/L and at least 80 nmol/L in the third trimester when the fetus uses more vitamin D. So in reality, most people don’t have an optimal level of vitamin D for pregnancy.

Due to the higher requirement of vitamin D during pregnancy, if you’re currently deficient in vitamin D a prenatal vitamin is not enough to increase your levels. You will need a personalised treatment plan incorporating a vitamin D supplement to get the optimal dosage for you.

Complications associated with gestational diabetes

During pregnancy people who experience gestational diabetes are at an increased risk of preeclampsia, hypertension, early delivery, induction of labour and caesarean section. After pregnancy, people with gestational diabetes have an increased risk of developing type 2 diabetes mellitus.

You baby is at an increased risk of being born at a larger size and experiencing fetal hyperinsulinemia. However this is only a risk if your gestational diabetes isn’t well managed.

When gestational diabetes is appropriately managed, the risk of these complications is significantly reduced, and many people have a healthy pregnancy with gestational diabetes.

How can nutrition help with gestational diabetes?

Using nutritional therapy to manage gestational diabetes is the first course of action as many cases of gestational diabetes can be adequately managed in this way. Although an individual approach is important to the management of gestational diabetes, the general principles include:

Increasing the intake of foods that support improved insulin sensitivity
Ensuring adequate energy intake
Focusing on consuming low-GI carbohydrates rather than an exact amount of carbohydrates. Carbohydrates should predominantly consist of starchy foods with high dietary fibre content, such as vegetables, legumes, fruits, and whole grains. It is best to distribute carbohydrate intake throughout the day to avoid excessive amounts that result in postprandial hyperglycaemia.
Ensuring adequate intake of protein
Focusing on adequate intake of omega-3 and limited intake of saturated fats
Ensuring an adequate intake of vitamins B9 and D, calcium and iron
Maintaining physical activity

Supplements such as inositol and chromium can be useful in managing blood glucose levels. However it is important to see a practitioner before commencing any new supplements, particularly during pregnancy. There are also many strategies a clinical nutritionist can advise you on to manage your blood glucose levels if you are diagnosed with gestational diabetes.

Looking for advice to manage gestational diabetes? Book a consultation with Court!

If you’re interested in taking any supplements, please discuss this with your practitioner to ensure you’re taking the correct dose and form for you. This article is not intended to be medical advice and is purely for education purposes.