Gestational diabetes (diabetes in pregnancy)

Diabetes in pregnancy, medically called Gestational Diabetes or GDM, is common. Some data suggests that in South Western Sydney, the rate is close to 1 in 5 (18%). With good care most women have healthy pregnancies and healthy babies.

What is diabetes in pregnancy?

In pregnancy, hormones make it harder for your body to use insulin, so your blood sugar can rise.This can be:

• Gestational diabetes (starts during pregnancy), or

• Pre‑existing diabetes (type 1 or type 2 you had before conceiving).

Both need closer monitoring and tighter blood sugar control during pregnancy.

How is it diagnosed?

Most women have an oral glucose tolerance test (OGTT) at 24–28 weeks. You fast overnight, have a blood test, drink a sweet drink, then have more blood tests over 2 hours.If the results are above set cut‑offs, you are diagnosed with gestational diabetes.

Women with known diabetes or high risk (previous GDM, strong family history, higher BMI, certain ethnic backgrounds) are often tested earlier.

Why does control matter?

Good control greatly lowers the chance of problems for you and your baby.

If sugars are not well controlled, risks can include:

• For baby: very large size, birth complications, low sugars after birth, breathing issues and higher stillbirth risk.

• For you: high blood pressure, pre‑eclampsia, higher chance of induction or caesarean, and slower healing.

With early diagnosis, careful monitoring and treatment, many women with diabetes in pregnancy have straightforward pregnancies and births.

How is it managed?

With a private obstetrician, in conjunction with an endocrinologist, your care is usually very coordinated and personalised.

Typical elements include:

• Healthy eating: A dietitian can help you spread carbohydrates over the day, focus on high‑fibre/low‑GI foods, and avoid sugary drinks and large portions.

• Physical activity: If your obstetrician is happy for you to exercise, gentle regular walking or pregnancy‑safe exercise improves insulin sensitivity.

• Blood sugar checks: You’ll monitor with a finger‑prick meter and bring results to appointments so your obstetrician can adjust your plan.

• Medication if needed: If lifestyle changes are not enough, your obstetrician may start tablets or insulin. Insulin does not harm your baby and is often temporary.

With private care, you’ll usually see your obstetrician frequently, with extra growth scans and close review of your blood sugars, weight, blood pressure and baby’s wellbeing.

Timing and type of birth

Your obstetrician will individualise your birth plan based on:

• How well your sugars are controlled

• Baby’s growth and wellbeing

• Your blood pressure and any other conditions

• Whether you have gestational or pre‑existing diabetes

Common patterns:

• Well‑controlled gestational diabetes on diet alone may allow you to await spontaneous labour close to your due date, with induction discussed if you go over.

• If you are on insulin or baby is large, your obstetrician may recommend an induction or planned birth a little earlier.

• For women with pre‑existing type 1 or type 2 diabetes, birth is often planned around 38–39 weeks.

Your obstetrician will also discuss whether vaginal birth or caesarean is safest for you and your baby.

After birth and long‑term health

After birth, pregnancy hormones drop and blood sugar usually improves quickly.

• Gestational diabetes often settles, but you’ll need a repeat OGTT around 6–12 weeks after birth.

• If you had pre‑existing diabetes, your insulin or medications will be adjusted and you’ll continue long‑term follow‑up.

Having gestational diabetes increases your chance of developing type 2 diabetes later, and your child has a higher risk of obesity and diabetes as well.This makes the months and years after pregnancy important.

Key long‑term steps:

• Aim for a healthy weight with balanced eating and regular activity.

• Cut back on sugary drinks, large portions of refined carbs and frequent takeaway.

• Try to move most days – even short walks with the pram help.

• Have regular diabetes checks with your GP (usually every 1–3 years).

• Before a future pregnancy, see your GP and/or obstetrician early to plan and optimise your health.

A supportive private obstetrician, combined with an endocrinologist, your GP and allied health professionals, can guide you through pregnancy and help set you up for better health for the rest of your life and your child’s.