Gestational Diabetes – What you need to know!

By Dr Caroline Hoggenmueller, FRANZCOG

Understanding Gestational Diabetes

Diabetes is a condition where too much blood glucose is travelling through the blood stream. The hormone insulin moves glucose or sugar from your blood and into your body’s cells, where it is used for energy. 

Gestational diabetes is a type of diabetes which only occurs in pregnancy and affects 12-15% of all pregnant women in Australia.

In pregnancy, hormones produced by the placenta, which help your baby to thrive, make it harder for your body’s insulin to work properly. This condition is called insulin resistance. 
Gestational diabetes then develops when your body is unable to cope with the extra demand for insulin production, which results in high blood glucose levels.  

How is gestational diabetes diagnosed?

All pregnant women in Australia are offered a test for gestational diabetes between 24-28 weeks of pregnancy. This blood test is called glucose tolerance test. Should you have risk factors for gestational diabetes, you will be offered an early test at 14-18 weeks of pregnancy.

It’s a 2-hour blood test which requires you to be fasting overnight. After an initial blood test, you will then be given a sugary drink and your blood sugar levels will be tested at 1 hour and 2 hours after. Should the amount of glucose in your blood rise above normal levels, gestational diabetes is then diagnosed.

Who is at risk of gestational diabetes?

Gestational diabetes is very common; however, you are more likely to develop this condition: 

• If you had gestational diabetes in a previous pregnancy
• If you have given birth to a baby weighing more than 4.5 kg
• If you have parents or siblings with Type 2 diabetes
• If you are over 35 years old
• If your body mass index is 30 or higher
• If you have polycystic ovarian syndrome
• If you are of Aboriginal or Torres Strait Islander 
• If you are of Asian, Indian subcontinent, African or Middle Eastern ethnicity
• If you are taking certain types of corticosteroid medication or antipsychotic medication

Is gestational diabetes dangerous for my baby and myself?

Good news! Most women with gestational diabetes have an otherwise healthy pregnancy and are going to give birth to healthy babies.

However, in some cases gestational diabetes can cause serious problems, especially if it is not recognised or not treated properly.

Uncontrolled high blood glucose levels in the mother will make the baby having to produce more insulin, which can make your baby grow much bigger than normally anticipated. This may increase your likelihood of needing your labour to be induced as well as increasing your chance of a caesarean section. It also might increase the chance of your baby needing an admission to the Neonatal Unit to control baby’s low blood glucose levels after birth.

Very rarely, a poorly controlled gestational diabetes may cause serious birth complications and stillbirth. After birth, your baby may be at greater chance of developing childhood obesity and or diabetes later in life.

Controlling your blood sugar levels nicely during your pregnancy helps greatly to reduce these complications for you and your baby.

How is gestational diabetes managed?

When you are diagnosed with gestational diabetes, a team of dedicated healthcare professionals is there to assist you in managing this condition. 

In addition to your Obstetrician and Midwife you will be getting counselling from a diabetes educator as well as a dietician. You will be shown how to measure your blood sugar levels with a glucometer device and receive advise on target blood glucose levels for pregnancy. You will start receiving extra antenatal care and will have more visits to your Obstetrician and Midwife, where your tests results will be reviewed regularly. The most common times to check your blood sugar level will be first thing in the morning, when waking up, as well as 2 hours after meals.

In majority of cases, gestational diabetes is managed with healthy eating and exercise. In some cases, medication to help with lowering sugar levels is needed. 

Healthy eating and physical activity

The most important therapy for gestational diabetes is maintaining a healthy balanced diet and to exercise regularly, ideally every day. In majority of cases, this will improve your condition and help you having blood glucose levels in a normal range. Your dietician will advise you which food types to avoid. They will also educate you regarding a variety of nutritious healthy food choices, which help manage the gestational diabetes as well as your weight gain in pregnancy. 

Physical activity is greatly helpful in managing your blood sugar levels with the added benefit of helping with heart burn, back pain and constipation in pregnancy. 

Activities you could do every day are brisk walking, pregnancy Yoga or Pilates as well as swimming or aqua fitness classes. 

Medications to help with managing gestational diabetes

If you blood glucose levels are not manageable with a healthy diet and exercise alone, your Obstetrician or diabetes specialist might start you on medications to help lower your sugar levels. 

Some women might be recommended to use a tablet called Metformin, other women might be started right away on Insulin injections. Your diabetes educator will thoroughly educate you in the use of insulin. Your insulin doses will be reviewed regularly and might be increased slowly throughout the course of your pregnancy. 

Will my baby receive extra monitoring and when is the best time for my baby to be born?

Throughout your pregnancy your Obstetrician may recommend further ultrasounds to check on your baby’s wellbeing and growth. This will also help guide you and your team of professionals in managing your diabetes in the best way. The timing of birth of your baby will depend on your individual circumstances, however most babies of mothers with gestational diabetes will be born between 38-40 weeks. 

What happens after the birth? Will I have diabetes when I am not pregnant?

Your baby will stay with you unless other problems might have occurred throughout labour and delivery. Your midwife will assist you with breastfeeding, which is the best choice of nutrition for your baby. Your babies’ blood sugar levels will be checked regularly after birth and a Paediatrician will be involved in case of any concerns.

Gestational diabetes normally resolves after birth. Your Doctor or Midwife will check your blood glucose levels after birth in hospital. They will also organise another glucose tolerance test at 6 weeks after birth. Most women do not have Type 2 diabetes immediately after their pregnancy. 

However, it is important for you to maintain a heathy lifestyle, diet and normal body weight throughout your life. As many as 1 in 2 women, who had gestational diabetes in their pregnancy, will go on and develop Type 2 diabetes later in life. 

Further useful resources for you: 

• www.Baker.edu.au: Managing Gestational Diabetes
• www.NDSS.com.au: Understanding Gestational Diabetes
• www.diabetesaustralia.com.au: Managing Gestational Diabetes
• www.chsa-diabetes.org.au: Gestational Diabetes and Starting Insulin in Gestational diabetes
• www.eatforhealth.gov.au: Tips for eating well

Sources and Acknowledgement 

This information is intended as guidance and patient information only. It should not replace individual medical advice. Should you have concerns about your or your baby’s health, please contact your health professional about further advice. 

www.rcog.org.uk
www.nice.org.uk 
www.baker.edu.au
www.ndss.com.au
www.chsa-diabetes.org.au 
www.diabetesaustralia.com.au