Warning Signs Of Gestational Diabetes, What Causes It?

Spread the love

What is Gestational Diabetes?

Gestational diabetes, also known as gestational diabetes mellitus (GDM), refers to a type of diabetes which affects women during pregnancy. Diabetes is a condition where one’s blood glucose (sugar) level is too high. Due to placental hormones, glucose levels in the body increase, and as does resistance to insulin

It is quite common in Singapore, and up to 1 in 5 Singaporean women experience this during their pregnancy. In most cases, it develops in the middle or end of the pregnancy.

Signs and symptoms

For gestational diabetes, most women actually do not experience any symptoms.

However, when one’s blood sugar level becomes too high (hyperglycemia), she may experience some of the following symptoms: (do note that this is not an exhaustive list!)

  • Being unusually thirsty often
  • Having to urinate more than normal
  • Tiredness and nausea (similar to early pregnancy symptoms)
  • Dry mouth
  • Sugar detected in urine tests (which are conducted during visits to the gynaecologist)

Risk factors

A risk factor refers to something that can increase the risk of developing a disease, such as gestational diabetes.

Risk factors for gestational diabetes include:

  • Having a family member (parent or sibling) with diabetes
  • A body mass index (BMI) greater than 25kg/m2.
  • Having a history of GDM in previous pregnancy
  • Having a previous baby that weighed more than 4kg at birth
  • Known prediabetes — prediabetes refers to when blood sugar levels are above normal, but not high enough to be diagnosed as type 2 diabetes
  • Being 40 years old or more
  • Having an unhealthy diet, excess intake of sugars & carbohydrates
  • Polycystic ovarian syndrome (PCOS) — a type of condition where the women has hormonal imbalances

If one has the above risk factors, it would be good to go for screening of gestational diabetes at 24 to 28 weeks of pregnancy!


Most women are able to have healthy pregnancy and delivery despite having gestational diabetes if their blood glucose levels are well controlled. However, if the blood glucose levels are not well controlled, certain complications could arise for both the mother and baby:



During pregnancy

–        Miscarriage

–        Pre-eclampsia (refers to having high blood pressure during pregnancy)


–        Preterm birth

–        Stillbirth

–        Growing bigger than normal

–        Excessive amniotic fluids[1]

At delivery

–        Induced labour

–        Caesarean section

–        Increased chances of injury

–        Increased chances of injury

–        Shoulder dystocia (refers to when the baby’s shoulder gets stuck in the mother’s pelvis)

–        Breathing difficulties

After delivery

–        Having a higher risk of developing


Diabetes later in life

–        Wound complications

–        Low blood glucose levels

–        Blood mineral imbalance

–        Requiring extra care at the neonatal unit[2]

–        Jaundice (yellowing of skin)

–        Having a greater risk of developing obesity or diabetes in the future


For the diagnosis of GDM, an oral glucose tolerance test (OGTT) is required. In Singapore, all pregnant women will be offered screening for GDM through this test, which is usually performed between 24-28 weeks of pregnancy. This may be performed earlier if one has risk factors related to GDM, and repeated again at 24-28 weeks if the first test was normal.

How is the OGTT carried out?

  • Fasting from 12 midnight the night before the test.
  • A fasting blood sugar test will be taken when one arrives at the clinic.
  • Following that, they will be given a 75 g glucose drink that should be consumed within 5 minutes.
  • Blood glucose test will then be repeated 1 hour and 2 hours after consuming the glucose drink.

All pregnant women are encouraged to undergo the OGTT as GDM is a common condition and can cause complications!

Blood glucose levels which indicate gestational diabetes:

  • Fasting venous plasma glucose ≥ 7.0 mmol/l
    • This indicates the value obtained after the fasting from midnight
  • 2-hour venous plasma glucose ≥ 7.8 mmol/l
    • This indicates the value obtained 2 hours after consuming the glucose drink
  • Casual venous plasma glucose ≥ 11.1 mmol/l
    • This indicates the value obtained at a test taken at a random time (without any fasting or recent eating prior to the test)

Women who develop gestational diabetes are more likely to have problems during their pregnancy and delivery. If you or someone you know is pregnant, be on the lookout for these symptoms of gestational diabetes. If you think that you may have developed this condition, don’t hesitate to consult your doctor. The sooner it can be diagnosed and treated, the better it will be for both mother and child.

Be sure to share this information with your friends who might also be pregnant so they can keep an eye out for these warning signs as well.