Pregnancy Care

Diabetes During Pregnancy: What You Need to Know


In Singapore, Gestational Diabetes Mellitus (GDM) is very common and affects about one in every five pregnant women. Women who have uncontrolled GDM are at an increased risk of certain conditions during pregnancy such as high blood pressure, preterm labour and other pregnancy complications. Having had GDM during pregnancy will put the mother at an increased risk of developing type 2 diabetes and the exposure of high sugar levels in utero, will increase the child’s risk of developing obesity and type 2 diabetes later in life.

What Causes Gestational Diabetes Mellitus?

Lots of changes happen to the body during pregnancy.

Along with the physical signs, the hormones that are produced during pregnancy can make it hard for the body to use insulin properly. This puts the woman at an increased risk of insulin resistance. During late pregnancy, all pregnant women experience some insulin resistance. Although most pregnant women are able to produce enough insulin to overcome insulin resistance, some are unable to do so. This makes it difficult to use glucose (sugar) properly for energy, so it stays in the blood and the sugar levels rise. This then leads to gestational diabetes mellitus (GDM).

In order to diagnose gestational diabetes in pregnant women, an Oral Glucose Tolerance Test (OGTT) is performed between 24 and 28 weeks of pregnancy. The 75g OGTT should be performed in the morning after an overnight fast of at least 8 h. The diagnosis of GDM is made when any of the following plasma glucose values are met or exceeded:

  • Fasting: >5.1 mmol/L (92 mg/dL)
  • 1 h: >10.0 mmol/L (180 mg/dL)
  • 2 h: >8.5 mmol/L (153 mg/dL)


Symptoms of Gestational Diabetes Mellitus

For most women, gestational diabetes doesn’t cause noticeable signs or symptoms. When sugar levels are very high, some symptoms may include:

  • Increased, frequent urination
  • Increased thirst
  • Feeling tired or nauseous (which can be similar to early pregnancy symptoms)
  • Sugar detected in urine tests (conducted during prenatal visits)

Risk Factors for Gestational Diabetes Mellitus

Gestational diabetes is more common in women with the following risk factors:

  • Obesity, high Body Mass Index (BMI) of over 30kg/m2.
  • Lack of physical exercise.
  • Had gestational diabetes in previous pregnancies.
  • Has Polycystic ovary syndrome (PCOS)
  • Family history of Diabetes.
  • Having delivered a baby weighing more than 4.1 kilograms in the past

Consequences of Not Controlling Gestational Diabetes Mellitus

It is important that diabetes during pregnancy be managed properly. Uncontrolled gestational diabetes can result in dangerously high blood sugar levels that can cause issues for both mother and baby, including an increased risk of requiring a C-section delivery.

Complications to the Baby

  • Overweight at birth. Blood sugar levels that are higher than normal during pregnancy can cause the baby to grow overly large. Large babies are more prone to become trapped in the birth canal, suffer birth injuries, or require a C-section.
  • Premature (early) birth. High blood sugar levels may increase the risk of a woman going into labour early and giving birth before her due date.
  • Breathing troubles that are severe. Premature babies whose mothers have gestational diabetes are at risk of developing respiratory distress syndrome, which causes breathing difficulties in the baby.
  • Blood sugar levels are low (hypoglycemia). Shortly after birth, babies born to mothers with gestational diabetes may experience low blood sugar (hypoglycemia). Severe hypoglycemia can result in convulsions in the baby. Therefore, such babies may need close monitoring shortly after birth.
  • Obesity and type 2 diabetes are more likely to develop in children whose mothers had gestational diabetes.
  • Stillbirth. Poorly controlled gestational diabetes can lead to the death of a baby before or soon after birth.

Complications to the Mother

  • High blood pressure and pre-eclampsia. These become life-threatening for both mother and child.
  • Having a surgical delivery (C-section).
  • Getting diabetes in the future. If you have gestational diabetes, you’re more likely to get it again in your next pregnancy. Furthermore, you are at a higher risk of developing type 2 diabetes as you get older.

Preventing Gestational Diabetes Mellitus

You can’t prevent it but there are some things you can do to reduce your risk. This includes managing your weight, eating healthily and keeping active before pregnancy.

There are a few things expectant mothers and future mums-to-be can do to lower their risk of gestational diabetes:

  • Eat good food sources. Pick food sources that are high in fibre and low in fat and calories. Try to increase intake of food high in fibre, vegetables and whole grains. Watch portion sizes closely and be sure to have a balanced diet.
  • Stay active. Exercising before and during pregnancy can lower your risk of developing gestational diabetes. Aim for 30 minutes of moderate exercise, 5 days of the week.
  • Start pregnancy at a healthy weight. Assuming you’re planning to get pregnant and you are currently overweight, losing additional weight in advance might assist you with having a better pregnancy outcome. Take steps to make improvements to your dietary patterns that can help you through pregnancy, such as, eating more vegetables and food high in fibre. Try to lose the extra weight at least 3 to 6 months before conceiving.
  • Try not to put on more weight than suggested. Putting on some weight during pregnancy is normal. However, gaining a lot of weight excessively and fast can increase your risk of developing gestational diabetes. Seek help from a medical professional if you have any concerns about excessive weight gain.


Gestational Diabetes Mellitus (GDM) can be harmful to both mother and child if left untreated. By going for regular check-ups, monitoring of glucose levels, maintaining a healthy weight and having a balanced diet, one can decrease their chances of serious health complications resulting from GDM.

At SOG, our team of O&G and Endocrine specialists are ready to help you throughout your pregnancy journey.


About SOG Health Pte. Ltd.

Established in 2011, SOG Health Pte. Ltd. (“SOG”) is a leading healthcare service provider dedicated to delivering holistic health and wellness services to the modern family.

With a long and established track record in Singapore providing Obstetrics and Gynaecology (“O&G”) services such as pre-pregnancy counselling, delivery, pregnancy and post-delivery care, the Group has since further expanded its spectrum of healthcare services to include Paediatrics, Dermatology, and Cancer-related General Surgery (Colorectal, Breast & Thyroid).

The Group’s clinics, under its four operating segments of O&G, Paediatrics, Oncology and Dermatology, are strategically located throughout Singapore to provide easy access to its patients.

  • Obstetrics
  • Gynaecology
  • GynaeOncology
  • Breast, Thyroid & General Surgery
  • Colorectal, Endoscopy & General Surgery
  • Dermatology
  • Paediatrics

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