32 – 36 weeks the toughest time…

My levels have gone crazy?!

Between 32 – 36 weeks are what we know to be the toughest time for gestational diabetes. It’s at around this point that we typically see insulin resistance worsen. You think you have your gestational diabetes diet sussed out and you can literally wake and eat the same breakfast you’ve been tolerating well for weeks on end and get crazy blood sugar levels?!

32-36 weeks the hardest time

What the heck is going on and what did you do wrong???… Firstly, you’ve done NOTHING wrong! This is to be expected and is completely normal and typical with gestational diabetes.

To understand what’s going on, we need to understand a bit about gestational diabetes and how it works…

Gestational diabetes is a progressive condition

Gestational diabetes typically presents itself between 24 – 28 weeks. It is for this reason that it is around this time when screening for gestational diabetes typically takes place. It should be noted that insulin resistance can be detected much earlier than this time also, especially in subsequent pregnancies where the mother previously had gestational diabetes. Many ladies are told that earlier diagnosis means that they may have undiagnosed Type 1 or Type 2 diabetes. We have found that this is not the case when ladies are tested following the birth of their baby and so we advise not panicking and waiting until you have your post-birth diabetes testing before causing yourself too much distress. Further information on post-birth diabetes testing can be found here.

Gestational diabetes is caused by increased hormone levels from the placenta that cause insulin resistance. Those diagnosed with gestational diabetes are not able to increase insulin production to meet the additional requirement, or they cannot use the insulin which has been made effectively and so blood sugar levels remain too high. For further information on diagnosis, see this page.

At around 26 weeks large amounts of cortisol are released. Cortisol is a hormone which causes high insulin resistance, meaning there is a raise in blood glucose levels and is where most will be diagnosed. If you were diagnosed earlier than 26 weeks, then you may see a big raise in insulin resistance at around this time.

increasing insulin resistance in pregnancy

Following diagnosis, levels may fluctuate, and there may be times when insulin resistance eases slightly and doesn’t seem as bad. Then insulin resistance increases and levels worsen again. Or you may have slight insulin resistance which doesn’t even show in your daily tests and you question whether you actually have gestational diabetes or not.  Many start to get to grips with gestational diabetes diet and their level of insulin resistance, then BOOM! They hit 32 weeks and it can go a bit pear-shaped! Readings may start creeping up or for some, they may rocket.

What happens at 32 – 36 weeks and why is it the toughest time?

You already have insulin resistance and then at around 32 weeks there is a rise in Progesterone hormone levels and insulin resistance can crank up to another gear. It is also why some mothers with previous negative GTT [glucose tolerance test], are then re-tested and have positive test results at around this time (along with the rapidly growing baby which is making your placenta work harder and pushes out more insulin-blocking hormones).

Gestational Diabetes: Detection, Management, and Implications

Cortisol has the highest diabetogenic potency and has peak effect at 26 weeks gestation. Progesterone also has relatively strong anti-insulin properties that peak at 32 weeks gestation

The Diabetogenic Potency of Hormones in Pregnancy

Hormone  Peak elevation (weeks) Diabetogenic potency
Very weak
Very strong


How to bring levels down after a high reading

If you get an over-target blood sugar level, always wash your hands in just water and re-test to check that the level is accurate. Please note, different readings will appear with every single test taken as the monitor is just a guideline. But it should give you an idea if your levels are high. If you believe your levels are high then drinking lots of water helps to flush excess sugars through the body and exercise (any activity) for 20 minutes will help bring your levels back down. For more information and guidance on testing blood sugar levels, please take a look at this.

32 weeks, maybe time to re-evaluate

If you haven’t been following a strict GD diet, then now is the time to start looking at what you’re eating and making changes. If you have been following a GD diet, you may need to start to re-evaluate your meals and how well you are pairing your food.

If you are at the point where you are struggling to tolerate any form of starchy carbohydrate in small amounts, even when paired heavily, or you are struggling with ketones then it is time to call your diabetes team to discuss your increase in levels. 3 or more high readings within a week, is usually a good guide to go by.

For those already on medication and/or insulin it is around this point where doses may need to be severely increased.

“I wanted to stay diet controlled”

The words, “but I wanted…” or “was hoping to stay diet controlled” come up in our Facebook support group often and my answer is always the same; “of course you did. Not one member in the group WANTS to be taking medication or injecting insulin. But there is only so much you can do.”

Many mothers feel like a failure when they need to start medication or insulin to help lower and stabilise blood sugar levels. If you’re a failure then so am I and so are all of us that ended up on medication or insulin! So stop saying you’re a failure – how exactly have you failed?

Just because you need to start the medication to help control your blood sugar levels does not mean you’ve failed! If that’s the case, I failed early on in my first pregnancy, at 13 weeks in my second pregnancy and from day 4 in my last pregnancy! In fact, my whole Facebook admin team are a failure if you class needing medication to control blood sugar levels a failure.

Please remember that many mothers who are diagnosed may need to go straight onto medication and/or insulin and are not even given a chance to try diet control. Does that make them failures from the word go? NO. Many mothers diagnosed with gestational diabetes will need help with medication to achieve lower levels.

Diet-controlled mothers are not trying harder or doing better because they have managed to control the condition by making changes to diet and exercise alone. They simply do not have insulin resistance ‘as bad’. Going on metformin or insulin does not mean that you can eat whatever you like. It means you should be able to eat the same diet as a diet-controlled mother.

QUESTION. Would you feel you failed if you needed to take medication for other illnesses and ailments? e.g. antibiotics for an infection that you can’t get rid of on your own? Have you failed if you need to take iron tablets, or tablets for high blood pressure? Why is gestational diabetes any different?

Gestational diabetes is not a cold or a headache where you can try to just get on with it, not take the paracetamol and struggle through it. If you need help to lower your blood sugar levels, then unfortunately you need that help – it is for the safety of your growing baby. That doesn’t make you a terrible mother or a failure.

To learn more about medications used to help lower and stabilise blood sugar levels, you can see further info on our Metformin for gestational diabetes page and our Insulin for gestational diabetes page.

After 36 weeks

Many mothers with gestational diabetes see a natural drop in blood sugar levels after around 36 – 37 weeks. After this time, the release of hormones slows down and eases off meaning insulin resistance may improve slightly and your blood sugar levels may start to normalise, requiring a reduction in insulin therapy if you have been using insulin and you may need to increase the number of carbohydrates eaten to keep levels stabilised.

Remember that ‘good’ blood sugar levels are not the concern, but a dramatic drop and/or levels not raising after eating and frequent hypos can be a concern of placenta deterioration. To learn more about placenta deterioration with gestational diabetes and the symptoms to look out for, then take a look at our page here.

NOTE: The placenta naturally ages at the end of the pregnancy and so improved blood sugar levels can be a sign that your pregnancy is coming towards an end and the baby may be getting ready to appear!

If you have any concerns over gestational diabetes placenta issues or dropping blood sugar levels then you should discuss these with your health care professionals. It is not worth sitting, questioning and worrying, give your diabetic team a call and discuss your concerns.

It’s gonna get harder before it gets easier. But it IS going to get better, you just gotta make it through the hard stuff first

(and we’ll help you every step of the way!)