Gestational Diabetes: What You Need to Know

Some women may develop gestational diabetes in their second trimester, usually after week 24. Find out what causes it and how you can manage it

By Dr Tan Shu Qi, Consultant and Associate Professor Tan Thiam Chye, Visiting Consultant, Department of Obstetrics and Gynaecology, KK Women's and Children's Hospital

Gestational diabetes mellitus (GDM) happens when the body does not produce enough insulin, or when insulin is not used effectively due to natural bodily changes occuring in pregnancy. When that happens, you can't effectively burn glucose to energy. This causes a build-up of glucose in the blood, also known as hyperglycaemia.

If you're diagnosed with GDM, you must monitor your blood glucose levels during your pregnancy. Here's some basic information about this condition:

Who is at Risk?

who is at risk who is at risk of gestational diabetes

Any woman can develop gestational diabetes. However, if you're ≥40, have a family or personal history of diabetes or are overweight, you are at greater risk.

How to Test for GDM?

how to test for GDM

You will need to undergo an oral glucose tolerance test (OGTT). After a night of fasting, you will take a fasting blood sample. You'll then be given a sweet drink, and a repeat blood test will be done at one- and two-hour intervals. These tests will be used to determine your blood glucose reading.

What is a Healthy Blood Glucose Reading?

healthy blood glucose reading what is a healthy blood glucose reading

The ideal targets for expectant mothers with GDM are 4.5-5.5mmol/L pre-meal and bedtime, and 5.5-6.6mmol/L 2 hours after meal.

How Common is GDM?

how common is GDM

It's not as uncommon as you think — one in five mothers has gestational diabetes during pregnancy. In fact, it is recommended that all pregnant women get screened for gestational diabetes starting from week 24 of pregnancy so the outcomes can be better managed.

Is It Permanent?

is it permanent

The good news is, diabetes in pregnancy will more often than not resolve after the delivery. However, it may persist in a small group, where mums will need long-term follow-up and treatment. Make time for the follow-up OGTT as it is key to detecting diabetes early.

Visit Parent Hub, for more useful tips and guides for a healthy pregnancy.

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Sources:

The New Art and Science of Pregnancy and Childbirth 2008, World Scientific

Healthy Start for your Pregnancy 2012, Health Promotion Board Singapore

This article was last reviewed on 20 Jun 2023