The long & short of it

We require insulin to lower our blood sugar which increases when we eat food, and to make it available to our muscles, brain, and other tissues so we can function. If our body cannot lower its blood glucose levels adequately we are in a diabetic state. When a woman is pregnant, hormones released by the placenta place the body in an insulin resistant state to make sure the maternal body feeds the foetus enough glucose to grow. Because of this the blood sugar levels in the body can become higher than normal and need to be managed through diet and exercise.

A quick anatomy lesson…

The pancreas is the organ responsible for creating insulin. When we eat food, sugar in the form of glucose enters the blood stream. From there it is either taken up by the cells for storage or used for energy to do work, like walking around. When the level fo glucose in the blood increases the pancreas secretes insulin. This insulin travels to the cells of the body and essentially acts like a key in a lock. It allows the cells “gateways” to open and glucose to be transferred from the blood to the cells. As this happens our blood glucose level lowers and the body returns to normal.

What happens to this process during pregnancy?

When a woman is pregnant her body becomes naturally less insulin sensitive. The insulin does not work as effectively as when a woman is not pregnant. This happens because additional glucose is needed in the blood to circulate from the mother through the umbilicus to the baby, to allow it to grow properly. To do this the placenta, which surrounds the baby, releases a hormone that interferes with the mother’s sensitivity to insulin. This ensures that by increasing the amount of glucose in the blood there will always be glucose for the foetus to use and therefore to grow. This has the unfortunate effect of leaving the mother with frequently high blood sugar levels.

I’ll pause here to say that if you only take one thing away from this blog piece, let it be that a pregnant woman is in a naturally insulin resistant state to make sure her baby gets enough energy to grow. This will affect some pregnant women more than others. You need to know, it is not your fault. You did not do anything wrong. And you can do something about it.  

Now back to the pregnant body.

When glucose enters the mothers body the pancreas release insulin to move the glucose from the blood into the body’s cells. But when a woman is pregnant, her body becomes insulin resistant and not as much glucose can be removed from the blood. As a result, the pancreas produces more insulin which can temporarily lower blood sugar, but eventually these cells become overworked and can’t keep up with the demand for more and more insulin. When these cells stop working or aren’t functioning well enough to keep up with demand, blood sugar levels remain too high and the result is gestation diabetes.

How do I know if I have gestational diabetes?

Blood sugar levels are measured by either a fasting blood glucose test or a oral glucose test. A fasting blood glucose test, involves not eating for a period of time and then testing your glucose levels to see if it is higher than it should be when no food is coming in. It can also be measured via an oral glucose test where you are given a sugar filled drink and your body’s response to using that glucose is measured. You are classified as diabetic if your body fails to take enough of the glucose out of your blood within a certain period of time.

It is extremely important that pregnant women take these tests because it is unlikely they will have any other symptoms of diabetes. The tests are done between 24-28 weeks of the pregnancy.

Risk factors & complications

While many women with gestational diabetes will have a normal healthy pregnancy, left unmanaged the condition can cause problems for mother and child. Mothers can develop high blood pressure, increased risk of infection, increased likelihood of caesarean section, and an increased risk of type 2 diabetes later in their lives. Risks for the baby include a higher birth weight, increased risk of stillbirth, low blood sugar when born, and a future risk of childhood obesity.

What can I do?

The most important management modality for gestation diabetes is diet and exercise.

Diet will reduce the amount of glucose that gets into the blood and exercise helps to use up excess glucose by storing it and using it for energy.

How does exercise help?

Research shows that regular exercise participation is likely to reduce the risk of pregnancy complications. Physical activity also reduces the likelihood of gestation diabetes becoming type 2 diabetes later in life. 30 minutes of exercise on most, if not all days, is now a standard recommendation for pregnant women.

Exercise works to help diabetes in a number of ways. First, it makes our bodies more sensitive to insulin or, in the terms used above, less insulin resistant. Secondly when we do resistance exercise (strength training) our cells are able to use glucose more efficiently without insulin needing to bind to receptors, in the words used above, we no longer need the key to open the door. Therefore, even if you are in an insulin resistant state, your body will still be able to use the additional sugar in your blood.

Both these things can contribute to decreasing the level of glucose in the blood. Exercise is generally said to lower blood glucose levels for up to around 48 hours and so it is good to do exercise at least every two days or more often. Thirty minutes of exercise every day is now a standard recommendation for pregnant women, including strength training.

Final say:

It’s common for pregnant women to blame themselves if they are diagnosed with gestational diabetes. But if you are diagnosed, it is important to remember that this condition is not your fault. Most women diagnosed with gestational diabetes go on to have a normal pregnancy and delivery, and produce a healthy baby.

Also remember you can do something about reducing the effects of gestational diabetes, especially by exercising.

To manage your condition, get help from accredited allied health professionals such as a dietician and an exercise physiologist (come and see us!) to make sure you’re doing the right thing for yourself and your child.

Prenatal STRONG (Strength & Conditioning) is a class that is safe for all stages of pregnancy and is run by our Accredited Exercise Physiologists. Alternatively, you can see us 1:1 for exercise prescription, guidance, a home program an/or advice.


Written by Najwa Allen AEP ESSAM

Naj is an accredited Exercise Physiologist and has a personal interest in Type II Diabetes/GDM and using exercise to safely manage this condition