What it actually means for your baby, and why your story isn’t written in stone.
When I found out I was pregnant with my second baby, it was so unexpected we nearly made a heartbreaking choice.
My HbA1c was 7.2%, and back then, I thought that was disastrous. I was terrified I’d harm my baby, that he’d have birth defects, that it was too late. We even considered ending the pregnancy out of pure fear and guilt.
But we didn’t.
We decided to keep going.
We did the best we could, day by day.
My beautiful boy is now 8 years old, strong, healthy, clever, and absolutely perfect.
Did my A1c stay textbook-perfect through that pregnancy? No. I was newly diagnosed with type 1 and had only just adjusted to using a CGM.
But I learned, I adjusted, I did my best, and he’s here today, living proof that your baby is stronger than you fear.
So if you’re reading this and panicking about your numbers: please know I see you. Yes, your placenta matters. Yes, your sugars matter.
But your baby is not fragile glass, and you have time, tools, and power to protect them, even now.
The Placenta: A Quiet Miracle
It’s easy to think of pregnancy as just “baby growing inside you”… but behind the scenes, your placenta is the true unsung hero. This temporary organ forms from the same cells that make your baby. By the end of your first trimester, it’s fully functional, acting like a mini life-support machine:
✨ It brings oxygen in and takes carbon dioxide out — just like lungs.
✨ It delivers nutrients, hormones, and antibodies — like a liver and an immune system.
✨ It clears waste products — like kidneys.
✨ It even makes hormones that help your body adapt to pregnancy and prepare for birth.
For nine months, your baby’s wellbeing depends on this remarkable connection between you both. And when you have type 1, type 2, or gestational diabetes, understanding how blood sugar affects this precious lifeline can help you make calm, confident choices.
What Happens When Blood Sugar Stays Too High
Many mums wonder: Why does high blood sugar even affect the placenta? Here’s what the science says — with real examples.
📌 1️⃣ Structural Changes
Studies show that when blood sugars run high for long periods, the placenta sometimes tries to “compensate.” It grows bigger than normal — this is called placentomegaly (PubMed). While bigger might sound better, it can actually signal that the placenta is less efficient at its main job: exchanging nutrients and oxygen.
What this looks like:
In practice, a larger placenta can mean your baby gets too much sugar and grows very large — a condition called macrosomia (birth weight above 4,000 grams). Or, if certain areas don’t get enough blood flow, parts of the placenta may underperform, risking restricted growth instead.
📌 2️⃣ Cellular Disruption
The placenta forms through cells called trophoblasts — they invade your uterine lining, build networks of blood vessels, and anchor the placenta securely. High glucose levels disrupt this finely tuned system.
In lab studies, hyperglycaemia changes how these cells multiply, develop, and function (PMC). One 2024 review even showed that glucose stress interferes with energy production inside trophoblast mitochondria, which can slow down healthy growth (TGFβ1 Study).
Real-world result:
If blood vessels don’t grow robustly enough, oxygen delivery can drop. Babies may show signs of mild chronic stress, needing closer monitoring to check growth and amniotic fluid levels.
📌 3️⃣ Oxidative Stress & Inflammation
Diabetes can increase oxidative stress — a state where harmful molecules (free radicals) damage healthy cells. In the placenta, this stress triggers low-grade inflammation and mitochondrial trouble, harming how cells generate energy for all the work they do.
Studies like the Placental Morphology in Stillbirths paper found that these stress processes are linked with placental lesions like chorangiosis (too many small blood vessels due to chronic low oxygen) or villous immaturity, which can signal the baby isn’t getting what they need (PubMed).
Real Risks — Not Just Theory
So what does this mean for real mums? Historically, poorly controlled diabetes was linked to tragic outcomes:
🔎 In the early 2000s, stillbirth rates for mothers with type 1 or 2 diabetes were about 16–23 per 1,000 births — nearly four times the rate for pregnancies without diabetes (Systematic Review).
Other risks included:
• Preterm birth
• Preeclampsia (dangerous high blood pressure)
• Babies needing NICU time for breathing support or blood sugar problems
But that was then. Today’s landscape is completely different.
How Modern Diabetes Care Changed Everything
If you feel frightened reading those older stats, pause and take this in: modern tools and knowledge mean these outcomes are far less common when diabetes is well-managed.
🔬 The CGM Revolution:
Continuous Glucose Monitors (CGMs) have transformed how we catch blood sugar swings. A 2024 study showed CGMs reduced average HbA1c in pregnant women and improved baby outcomes — fewer big babies, fewer C-sections, and better placental health (PubMed).
🔬 The Power of Insulin Pumps:
Smart pumps and closed-loop systems mean fewer big highs and scary lows. Predictive Low-Glucose Suspend (PLGS) tech stops insulin delivery automatically to avoid crashes — protecting both you and the placenta.
🔬 Preconception & Early Control:
Preconception clinics focus on getting blood sugars stable before pregnancy for a reason. US research shows the risk of birth defects rises sharply only when HbA1c is above 9.5% during the peri-conception period. If your HbA1c is below this level, the risk of congenital anomalies is much lower and close to that of the general population. That’s why early planning and good control make such a difference for healthy outcomes. (Source)
But What If You Found Out Late?
Here’s where many mums freeze with guilt: “I didn’t know. I was 20 weeks before I found out. I must have harmed my baby.”
Take a breath. The truth? Research shows it’s not too late.
✅ The HAPO Study:
This huge study tracked 23,000+ women. It proved glucose levels in the second and third trimester strongly affect outcomes like baby size and birth complications — meaning that lowering sugars after diagnosis still protects your baby and placenta (HAPO Study).
✅ The Kristensen Type 1 Cohort:
A 2021 study in Diabetes Care followed type 1 mums who improved control mid-pregnancy. They saw fewer preterm births and better baby outcomes than mums who stayed poorly controlled — even if first-trimester HbA1c was high (Source).
✅ NICE Guidelines:
The UK’s gold standard guidelines for diabetes in pregnancy confirm: tight glucose control at any point in pregnancy reduces stillbirth, preterm birth, and other risks. (NICE NG3)
So if you found out halfway through — yes, your A1c may have been high — but every day you act, you reduce risk. It really does matter.
How To Support Your Placenta — Practical Steps
1️⃣ Monitor Like a Pro:
Use a CGM if you can. It shows you when sugar climbs before you feel it.
2️⃣ Aim for Target Ranges:
Many specialists suggest fasting sugars under 95 mg/dL (5.3 mmol/L), and 1-hour post-meal under 140 mg/dL (7.8 mmol/L) during pregnancy.
3️⃣ Balance Carbs + Fiber:
Pair healthy carbs with fiber and protein to slow down glucose spikes.
4️⃣ Gentle Movement:
Walking or prenatal yoga helps your insulin work better.
5️⃣ Build Your Team:
Endocrinologist, dietitian, diabetes nurse, high-risk OB, together they can help tweak your plan in real time.
The Real Bottom Line: Science + Self-Kindness
Your placenta is powerful! AND so are you. Yes, diabetes brings real risks, but today’s tools, research, and teamwork mean mothers with type 1, type 2, or GDM have healthier pregnancies than ever before.
If you found out late, please don’t dwell on guilt for yesterday. Focus on what you can do today — because the evidence is clear: each day you manage your sugars is a gift to your placenta and your baby.
📌 Need Extra Support?
I know how heavy this can feel — I’ve been there too.
That’s why I created my hypnobirthing support especially for mothers with type 1 and diabetes. I help you understand your body, lower fear, and feel calm and confident in every step.
✨ Join my next online relaxation class here
✨ Book a private birth coaching session here
✨ Or simply reach out and say hi, you’re not alone.
👉 Book your free consult or join here.