Gestational Diabetes (GDM) is diagnosed when higher-thannormal blood glucose levels(BGLs) appear during pregnancy. It usually develops around weeks 24 to 28 when it is detected by an oral glucose tolerance test, however GDM is temporary and the mother’s BGLs normalise after the pregnancy.

The release of hormones produced by the placenta for the baby’s growth and development causes GDM. These hormones block the action of the mother’s insulin, resulting in insulin resistance. When pregnant, the mother’s need for insulin also doubles
or triples, placing further strain on the body’s ability to produce insulin.

Although BGLs normalise after pregnancy, GDM identifies the mother at higher risk of developing type 2 diabetes in the future if she again develops insulin resistance.

Although a healthy lifestyle can lower the risk of developing GDM, there are
other risk factors and not all can be helped in late pregnancy:

• being over 30 years of age
• overweight or obese
• a certain ethnicity
• having a family history of type 2 diabetes
• gestational diabetes in previous pregnancies, some women have GDM in one pregnancy but not in others.

Many women with GDM are often unsure about which exercise is safe for them and their baby during pregnancy. Always check with your obstetrician if you are clear to exercise but here are some safety guidelines:

1. Exercise at moderate levels, until you are puffing but not speechless.
2. Exercise often – especially if diagnosed with GDM. Your insulin sensitivity increases for up to 24–48 hours after exercise. If you feel especially fatigued, nauseous or physically limited during pregnancy, walk just 10 minutes three times a day.
3. Exercise safely. Choose an activity with lower risk of injury, especially if you
   have GDM.
4. Maintain your exercise levels but expect your capacity to change – if you have been active prior to pregnancy, modify your regular program.
5. Be sensible – if you have not been a regular exerciser, take a more cautious but consistent approach of regular activity and increase your levels slowly.

Exercise in Pregnancy

It is important to include some exercise during pregnancy while also eating low-GI food and taking any prescribed diabetes medicines. Exercise improves insulin sensitivity and helps keep your BGL stable but also provides general health benefits –
better sleep, improved fitness for birth and nursing, improved mood and faster return to fitness.

If you haven’t been physically active before pregnancy, then aiming to become incredibly fit during pregnancy is unrealistic. Your physical
activity should help you become fitter than if you hadn’t exercised in pregnancy, and keep your BGLs more stable in the process!

Some safe exercise options are:

Swimming or water aerobics
A great cardio workout for maintaining muscle strength without impact/loading on joints

Pregnancy safe yoga
Not all postures in yoga are okay in pregnancy, so make sure the instructor knows you’re pregnant and adjusts the postures you perform

Antenatal classes
You can learn more about what happens to your body during pregnancy and meet other expecting mums.

Walking
With or without hills

Cycling
A stationary bike is best, especially in later stages when your balance changes. Be careful with continued pressure on your pelvic, which can create pelvic girdle pain.

Resistance training
Even if it is simply lifting yourself out of a chair. It maintains muscle mass, protects joints and can be modified for any stage of pregnancy. Again, stick to moderate intensity.

Exercising with GDM

If you are using insulin to manage your BGLs, remember that you are at more risk of a hypoglycaemic event or a ‘hypo’. This is where your BGLs fall too low, say below 4 mmol, and you start to feel unwell – dizzy, confused, sweaty and fatigued. Check with your endocrinologist about chances of a hypo if you are on glucose-lowering medication. Unfortunately these signs and symptoms are similar to those of exercise, which can make it hard to realise that you are having a hypo.

If you are taking insulin, try these simple steps to avoid a hypo:

• avoid exercising in the peak insulin action. Exercise is an insulin sensitiser, so can boost the impact of your insulin dose
• avoid injecting in the muscles you are exercising
• check your BGL 30 minutes pre-exercise. If it’s near 5, you may need to eat a little carbohydrate to avoid a hypo post-exercise
• check your BGL after exercise and again if you feel unwell
• stick to moderate-intensity exercise
• if you are commencing an new exercise program, go with a buddy who can keep an eye on you, or tell the instructor.

Every pregnancy is different, even for the same woman. Some involve extreme fatigue, others extreme nausea, insomnia, back/pelvic pain, heartburn, reflux and many more symptoms. The exercise you choose can be determined by some of them.

Expect your exercise capacity to change over the course of the pregnancy, so do what feels moderate on that day. Exercise is to get your BGLs under control and feel good about yourself, not make super-fit!

Above all, listen to your body – it’ll tell you if you are doing too much.

Christine Armarego ESSAM, MAppSci (Ergonomics), MAppSci (Rehab), is an Accredited Exercise Physiologist and Manager of The Glucose Club

This article was originally published in Conquest magazine published by Health Publishing Australia