What Is Gestational Diabetes Mellitus?
Gestational diabetes mellitus (GDM) is a type of diabetes that occurs during pregnancy and usually resolves after birth. It is caused by how your body processes glucose (sugar), leading to elevated blood sugar levels that can impact both your and your baby’s health.
Who Is at Risk of GDM?
According to RCOG Guidelines, GDM affects 4-5 in 100 pregnant women and there are some risk factors which include:
- Body mass index over 30 kg/m2
- Family history of diabetes (parent or sibling)
- Ethnicity - higher risk among South Asian, Black, African-Caribbean, and Middle Eastern backgrounds
- Previous large baby (4.5kg or more)
- History of GDM in a previous pregnancy
- Polycystic Ovary Syndrome (PCOS)
If you fall into one or more of these groups, your obstetrician may offer early screening with an oral glucose tolerance test (OGTT).
Why is GDM important?
While many women with GDM go on to have healthy pregnancies and babies, poorly controlled blood sugar levels can increase the risk of complications, such as:
- Increased likelihood of needing induction or caesarean section
- Adverse pregnancy outcomes (especially if the blood sugars are high), but the risk is reduced with proper management)
- Macrosomia (large baby), which can lead to delivery complications
- Shoulder dystocia during birth
- Preterm birth
- Preeclampsia
- Neonatal hypoglycaemia (low blood sugar in the baby after birth)
Additionally, mothers with GDM have a greater chance of developing type 2 diabetes later in life - making effective management all the more essential.
Learn: High-Risk Pregnancies - What you Need to Know
Managing GDM with Diet and Lifestyle
In most cases, GDM can be controlled through healthy eating, physical activity, and regular monitoring. Medication (such as metformin or insulin) may be needed if lifestyle changes alone don’t achieve the required glucose targets.
At Obstetric Care, the specialist team offers personalised support plans to guide you through every step, with a particular focus on evidence-based diet and lifestyle interventions.
1. Healthy Eating for GDM
Diet plays a central role in managing GDM. Our aim is to stabilise blood sugar levels by choosing foods that release glucose slowly and reduce insulin spikes.
Key recommendations include:
Choose Low Glycaemic Index (GI) Carbohydrates
- Whole grains: brown rice, oats, quinoa
- Sweet potatoes instead of white potatoes
- Wholemeal bread, pasta and crackers
- Legumes: lentils, chickpeas, beans
Pair Carbohydrates with Protein and Healthy Fats
- Examples: boiled egg on wholegrain toast, apple slices with peanut butter, Greek yoghurt with berries and seeds
Eat Regularly - Don’t Skip Meals
- Aim for 3 balanced meals a day and 2-3 healthy snacks to avoid blood sugar dips and spikes
Watch Your Fruit Intake
- Stick to one portion of fruit at a time, ideally paired with protein (e.g. a small banana with a few almonds)
Limit Sugary and Processed Foods
- Avoid sweets, sugary cereals, fruit juices, fizzy drinks, pastries and processed snacks
Stay Hydrated
- Water is the best option - avoid sugary drinks and limit caffeine intake as per expert guidelines
The key is to create manageable, sustainable food plans tailored to your needs and preferences.
2. Physical Activity
Gentle, regular exercise is another key pillar of GDM care. It helps your body use insulin more efficiently and keeps glucose levels steady.
Some safe and effective options include:
- Brisk walking for 20–30 minutes daily especially after meals
- Prenatal yoga or pilates (great for core strength and stress management)
- Swimming or aquanatal classes
- Stationary cycling
As always, it’s important to check with your obstetrician before starting any new exercise routine, especially if your pregnancy is considered high risk.
3. Blood Sugar Monitoring
You’ll likely be advised to check your blood glucose levels several times a day, typically:
- First thing in the morning (fasting level)
- 1 hour after meals
We can guide you on how to use a home glucose monitoring kit, interpret results, and make timely adjustments to your diet or activity.
Target blood sugar levels (as per NICE guidelines):
- Fasting: below 5.3 mmol/L
- 1 hour post-meal: below 7.8 mmol/L
If levels remain elevated despite lifestyle changes, medication may be required - my team and I will support you every step of the way with safe and effective options.
Learn: New National Guidance on Maternal Nutrition, Pregnancy Weight, and Exercise.
Obstetric Management of GDM
At Obstetric Care, we take a collaborative, proactive approach to managing GDM, involving:
- Monitoring maternal blood sugars and pressure
- Regular growth scans to check baby’s size and amniotic fluid levels
- Discussion of birth plans, with careful consideration of timing and mode of delivery
- Close postpartum follow-up, including a glucose tolerance test 6weeks after birth
Our goal is always to minimise complications while supporting your preferences as much as safely possible.
What Happens After Birth?
For most women, blood sugar levels return to normal shortly after delivery, especially if medication wasn’t required. However, follow-up testing is essential, as around 50% of women with GDM go on to develop type 2 diabetes in the future.
We offer:
- Postnatal glucose testing (usually at 6 weeks postpartum)
- Lifestyle advice for long-term prevention and monitoring
- Support with breastfeeding, which can also help stabilise blood glucose and aid postpartum recovery
How Obstetric Care Can Help
Being diagnosed with GDM doesn’t mean your pregnancy can’t be a healthy, positive experience - especially with the right support.
At Obstetric Care, we offer:
- Tailored care plans for women with GDM
- One-to-one consultations to guide you through diet, monitoring and pregnancy choices
- Close collaboration with dietitians, midwives and diabetes specialists
- A calm, understanding environment where you’ll feel empowered and informed
Whether you're newly diagnosed or simply want to prepare for a potential GDM diagnosis, we’re here to help you make confident, evidence-based decisions throughout your pregnancy.
Get in Touch
If you've been diagnosed with GDM or have risk factors that worry you, please don't hesitate to reach out. I am here to offer guidance, personalised care and peace of mind - so you can focus on enjoying this remarkable journey into motherhood.
Contact us today to arrange a consultation or learn more about our specialist pregnancy care services.
