Ep. 3: Blood sugar basics

If you’ve never had to think about your blood sugar levels before, a gestational diabetes diagnosis can feel like being dropped into a completely new language. Suddenly we’re talking numbers, fasting targets, post-meal readings - and most of us are left wondering what any of it actually means.

In this episode, Celia is joined by Melissa Tait - a credentialed diabetes educator and clinical nurse specialist with over 15 years’ experience supporting people with diabetes across hospital, community and telehealth settings. Together, they break down what blood sugar regulation actually is, what changes during pregnancy, and why gestational diabetes happens in the first place.

Melissa shares clear, practical explanations (including her much-loved “petrol tank” analogy), walks through the blood glucose ranges commonly used in pregnancy, and gently busts some of the myths that can lead to shame or self-blame. This conversation is informative, empowering, and designed to help you understand what’s happening in your body.

What you’ll hear in this episode:

• What “blood sugar regulation” actually means and how insulin works (in simple terms)
• Why glucose is essential for your body
• What happens when there’s too much or too little
• What hypoglycaemia (a “hypo”) is and how it feels
• How exercise, sleep, stress and sickness can influence your levels
• What changes during pregnancy and why insulin resistance increases
• Why gestational diabetes is commonly screened at 24–28 weeks
• Typical blood glucose ranges and why pregnancy targets are tighter
• Why you did nothing to cause gestational diabetes

Typical safe blood glucose ranges and targets

In someone without diabetes:

• Generally around 4.0–7.8 mmol/L across the day (≈72–140 mg/dL)

In gestational diabetes (Australian targets discussed in this episode):

• Fasting: ≤ 5.0 mmol/L (≤90 mg/dL)
• 2 hours after meals: ≤ 6.7 mmol/L (≤121 mg/dL)

Resources & links mentioned:

• Melissa Tait → click here
• Melissa on Instagram → @diabetes_educator_mel
• Connections Nerang → click here
• Australian Diabetes in Pregnancy Society (ADIPS) → click here 

About the guest

Melissa Tait is a credentialed diabetes educator and clinical nurse specialist with over 15 years of experience supporting people living with diabetes across Australia. She works across hospital, community and telehealth settings and is also a lecturer in diabetes education. Melissa supports people of all ages and stages - from young children to older adults - and has extensive experience guiding women through gestational diabetes with both clinical expertise and compassionate care. She is passionate about education, myth-busting, and helping women feel confident in understanding their bodies.

Transcript

This transcript was auto-generated and lightly edited for clarity.

Celia:
Blood sugar levels are something most of us never really have to think about - until suddenly we do. In this episode, we’re talking about what blood sugar regulation actually is and what changes once you're pregnant, to help you better understand what’s happening in your body. To help us do that, I’m joined by Melissa Tait.

Melissa is a credentialed diabetes educator and clinical nurse specialist. She has over 15 years’ experience across hospital, community and telehealth settings around Australia, and she’s also a lecturer in diabetes education.

Thanks so much for joining us, Melissa.

Melissa:
Thank you for having me. I’m very excited to chat about gestational diabetes and do a little bit of myth-busting.

Celia:
I just rattled off a bit of your CV, but can you tell us a bit more about the work you do in the diabetes field?

Melissa:
Sure. I’m a registered nurse by trade, and I completed a graduate certificate in diabetes education many years ago. Diabetes is a big umbrella term. Under that, we have gestational diabetes, type 1 diabetes, type 2 diabetes, and then all the technology that goes along with management - insulin pumps, continuous glucose monitors and so on.

I support people of all ages - from little ones through to people in their 90s. It affects everyone differently, and there are lots of different ways to manage it.

When someone is newly diagnosed, I teach them about their type of diabetes, how insulin works, medications, and I also provide a lot of mental health support. Diabetes is a long-term condition for many people, and even with gestational diabetes, I can spend quite a bit of time supporting women through pregnancy.

It’s a big education and support role - and I love sharing that knowledge.

Celia:
Let’s start at square one. When I was diagnosed with gestational diabetes, people quickly started talking about blood sugars. I’d heard the term before, but I didn’t really understand the process behind it.

Can you explain what blood sugar regulation actually is?

Melissa:
Definitely. When we eat carbohydrates - things like bread, rice, pasta, noodles, potatoes - they break down into glucose.

Glucose is our body’s energy source. We need it for our brain, heart, kidneys — all our organs to function.

When we eat, glucose enters the bloodstream. We need some glucose circulating, but it also needs to move into our muscles to be stored for later. The pancreas produces insulin, and insulin helps transport that glucose into the muscles.

I often explain insulin like a taxi or an Uber. It picks up the glucose from the bloodstream and carries it into the muscles - like filling up a petrol tank for later use.

Celia:
That analogy helps me a lot. I’ve heard it described as a key unlocking a door, but the taxi makes more sense in my brain - it transports it where it needs to go.

Melissa:
Exactly. So when everything is working well, we eat, the body makes the right amount of insulin, glucose is transported into storage, and everything stays in a safe range.

When someone has diabetes, there isn’t enough insulin to move that glucose effectively. So it stays in the bloodstream instead of getting into the muscles.

In type 1 diabetes, there’s no insulin being made.
In type 2 diabetes, there’s some insulin, but not enough.
With gestational diabetes, there is insulin being made - but it’s not enough to keep up with the increased demand in pregnancy.

Celia:
When glucose stays in the bloodstream, does it just stay there forever? Or does it eventually go away?

Melissa:
We always have some glucose circulating - we need it.

If levels rise too high, the body will try to compensate. Some people feel thirsty or tired because the energy isn’t getting into the muscles.

It’s very individual. Some people get symptoms, some don’t.

Celia:
And what about hypos - low blood sugar? What’s happening there?

Melissa:
A hypo, or hypoglycaemia, is when blood glucose drops below about 4 mmol/L.

People might feel shaky, sweaty, or unwell. If someone without diabetes skips a meal, they might feel hungry or shaky — but they won’t usually drop into a true hypo because their body can access stored glucose.

The body is very clever at correcting things.

Celia:
I’ve noticed since having gestational diabetes that I’m more aware of those fluctuations. It feels like there’s something happening in the background all the time.

Melissa:
That’s such a good way to describe it. Blood glucose levels are always fluctuating. They’re never one static number. They’re influenced by food, movement, sleep, stress, illness. After eating, levels rise - often peaking at about one hour - and then come back down over the next couple of hours.

When we’re monitoring, we’re looking for patterns. You’re not meant to sit at 5.9 all day. That’s not realistic.

Celia:
What changes in pregnancy?

Melissa:
Pregnancy hormones, produced by the placenta, are essential for baby’s growth - but they make you more insulin resistant. In some pregnancies, the body needs to produce two to three times more insulin to keep up.

If the pancreas can’t meet that demand, gestational diabetes develops.

This increase in insulin resistance tends to ramp up around 24–28 weeks, which is why we do the glucose tolerance test at that time.

Insulin resistance often continues increasing until about 36 weeks. Then hormone levels start to drop as baby prepares to be born, and some women notice their numbers become easier to manage.

Celia:
Between pregnancies, I’ve wondered whether there’s anything I can do to prevent gestational diabetes next time - beyond general healthy lifestyle choices.

Is there anything else you can do, or does it really come down to hormones?

Melissa:
There are known risk factors - previous gestational diabetes, family history, being in a larger body, age over 40. Lifestyle factors like movement and balanced eating help overall health, but I’ve also supported many young, active women with great lifestyles who develop gestational diabetes.

It really highlights how much of it comes down to hormones and how your body responds to them.

Celia:
For someone without diabetes, what’s considered a healthy range after a meal?

Melissa:
Generally:

• Fasting: around 4 to 5.5 mmol/L
• Two hours after eating: below 7.8 mmol/L

Levels rise after food - that’s normal - and then the body brings them back down.

Celia:
And what are the targets for gestational diabetes?

Melissa:
In Australia, we generally follow:

• Fasting: 5.0 mmol/L or below
• Two hours after meals: 6.7 mmol/L or below

The targets are tighter in pregnancy because elevated glucose can affect baby - potentially leading to higher birth weight, earlier delivery, or special care admission.

The goal is protecting both mum and baby.

Celia:
So I understand that in pregnancy we’re sharing glucose with baby, and baby has a developing pancreas. Is that why targets are lower during pregnancy?

Melissa:
Yes. If there’s extra glucose circulating, baby is exposed to that too. We want to keep levels in a safe range to protect both of you. And I always tell women - you’ve done nothing wrong to cause gestational diabetes. These hormones are helping baby grow. Your body just can’t quite keep up with the increased insulin demand.

Celia:
If there’s one thing you’d want women to take from this conversation, what would it be?

Melissa:
You did nothing wrong. Gestational diabetes is about hormones and insulin resistance — not willpower. Knowledge is power, and understanding what’s happening inside your body can make it feel less scary.

Celia:
Thank you so much, Melissa. I learned a lot.