Your ‘Need to Know’ Guide to Gestational Diabetes (GDM)

By Chloe Dymond Young - BANT Registered Nutritional Therapist, IBCLC and ex-Midwife (17 years).

Understanding Gestational Diabetes: Risks, Nutritional Factors, and Preparing Your Body Before Pregnancy:

Gestational Diabetes Mellitus (GDM) is a form of glucose intolerance first recognised during pregnancy. It affects roughly 5-15% of pregnancies globally and poses risks to both mother and baby if not managed well. But did you know that factors long before pregnancy like nutrition, genetics, and lifestyle can influence your risk?

This blog explores the latest research on the causes and risk factors for GDM, nutritional imbalances linked to increased risk, genetic predispositions, and practical ways to prepare your body before conception.

What Is Gestational Diabetes Mellitus (GDM)?

GDM is characterised by high blood sugar levels that develop during pregnancy in women who didn’t have diabetes before conception. It typically emerges in the second or third trimester, as hormonal changes increase insulin resistance.

While GDM often resolves after delivery, it carries risks for future type 2 diabetes for both mother and child.

Risk Factors for Gestational Diabetes: What Does Research Show?

1. Nutritional Deficiencies and Dietary Imbalances

• Vitamin D Deficiency: Low vitamin D levels have been linked to higher GDM risk due to vitamin D’s role in insulin sensitivity and glucose metabolism.

• Magnesium Deficiency: Magnesium helps regulate blood sugar, and inadequate intake is associated with insulin resistance.

• Excess Refined Carbohydrates and Low Fibre Intake: Diets high in simple sugars and low in fibre increase blood glucose spikes, contributing to insulin resistance.

• Imbalanced Fat Intake: Excess saturated and trans fats may impair insulin signaling, while omega-3 fatty acids appear protective.

2. Genetic Predispositions and Variants

Genetic variants influence susceptibility to GDM. Some key genes involved include:

• TCF7L2: Associated with insulin secretion and risk of type 2 diabetes, also linked to GDM.

• GCK (Glucokinase) gene mutations: Affect glucose sensing in pancreatic cells.

• IRS1 and IRS2: Involved in insulin receptor signaling, with variants linked to impaired glucose metabolism.

While genetics play a role, they interact with lifestyle and environmental factors.

3. Other Lifestyle and Physiological Factors

• Pre-pregnancy overweight and obesity: A major modifiable risk factor, increasing insulin resistance.

• Advanced maternal age: Risk rises with age over 35.

• Previous GDM or family history of type 2 diabetes: Increases likelihood of recurrence.

• Sedentary lifestyle: Physical inactivity contributes to poorer glucose control.

• Polycystic Ovary Syndrome (PCOS): Women with PCOS have a higher risk due to underlying insulin resistance.

How to Prepare Your Body Before Pregnancy to Reduce GDM Risk

Optimising health before conception is key to lowering GDM risk. Here are evidence-based strategies:

1. Nutritional Optimisation

• Vitamin D: Get tested for vitamin D status; supplement if deficient.

• Magnesium-Rich Foods: Include nuts, seeds, leafy greens, and whole grains.

• Balanced Macronutrients: Focus on low glycemic index carbohydrates, adequate protein, and healthy fats (like olive oil and omega-3 rich fish).

• Increase Dietary Fibre: Whole grains, legumes, vegetables, and fruits support glucose regulation.

• Limit Processed and Sugary Foods: Reduce intake of refined sugars, sweetened beverages, and ultra-processed snacks.

2. Physical Activity

Engage in regular moderate exercise, such as brisk walking, swimming, or prenatal yoga, to improve insulin sensitivity.

3. Weight Management

Achieve a healthy BMI before pregnancy through diet and exercise to reduce insulin resistance.

4. Address Underlying Conditions

Work with healthcare providers to manage PCOS, hypertension, or other metabolic issues.

Testing and Monitoring Before Pregnancy

• HbA1c: Gives an average blood glucose over the past 3 months; can identify prediabetes.

• Fasting Glucose: Assesses baseline blood sugar.

• Oral Glucose Tolerance Test (OGTT): Sometimes recommended preconception in high-risk women.

• Vitamin D and Magnesium Levels: To guide supplementation.

• Genetic Counselling: For women with a strong family history of diabetes or GDM can be helpful.

Final Thoughts

Gestational diabetes is a complex condition influenced by nutritional status, genetics, and lifestyle factors even before pregnancy begins. By focusing on optimising nutrient intake, managing weight, staying active, and working with healthcare professionals on appropriate testing, women can significantly reduce their risk.

If you’re planning a pregnancy, concerned about your risk of GDM or want to learn more about how nutrition supports a healthy pregnancy, I’d love to chat. I can help create a personalised plan to prepare your body for pregnancy and beyond - supporting both your health and your baby’s future health.

BOOK A FREE DISCOVERY CALL to find out if I can help you.