Pro-tip Series: Gestational Diabetes and Pregnancy

For our first post from our Pro-tip Series, MyMama has met (virtually, of course!) with resident Gynaecologist & Obstetrician Ms Christine Zammit Zerafa MD, MRCOG, EFOG-EBCOG, MSc Radiography (Ultrasound) to talk about a condition that pregnant women should be aware of.


Ms Christine Zammit Zerafa - Gestational diabetes and pregnancy


What is gestational diabetes?

Gestational diabetes (or its scientific term, gestational diabetes mellitus, GDM) may be defined as a disorder in the metabolism of carbohydrates, which develops for the first time during pregnancy.

2-5% of pregnancies are complicated by diabetes, mostly due to GDM.


How is GDM diagnosed?

Pregnant women with GDM may experience symptoms, including nausea, fatigue, frequent urination, unusual thirst, and vaginal and bladder infections. However, many of these symptoms may also happen in a normal pregnancy, so that it might be difficult to attribute these symptoms to GDM. Some women with GDM may experience no symptoms at all.

In view of this, all pregnant women are screened in order to increase the rate of diagnosis. All pregnant women will have their blood sugar levels checked (along with other routine blood tests) during the initial stages of pregnancy. Obstetricians carry out urine tests routinely on the pregnant woman at each antenatal visit, in order to check for the presence of sugar in the urine, which could mean that the woman is suffering from GDM.

Obstetricians will also identify pregnant women who are mostly at risk of developing the condition, and guide them on other investigations, which they need to carry out during the pregnancy.

A number of investigations may be done in order to aid in the diagnosis of GDM. The doctor will take a blood sample from the peripheral veins of the pregnant woman, which is then sent to the laboratory. Investigations may include:

  • Fasting blood glucose - As its name indicates, this test measures the blood sugar levels during fasting and is taken after the pregnant woman has refrained from eating for a couple of hours.
  • Random blood glucose - As opposed to the previous test, this test measures the blood sugar levels in a non-fasting state, so that the pregnant woman does not have to fast from oral intake before it is taken.
  • Haemoglobin a1c (Hba1c) - This test does not only measure the blood sugar levels at any point in time, but also gives an indication about the blood sugar levels over a period of time, before the test is taken.
  • Oral glucose tolerance test (OGTT) - During this test, the pregnant woman has to drink a solution, which contains sugar. The blood sugar levels are then checked at timely intervals.


What are the risk factors for GDM?

  • GDM in a previous pregnancy
  • BMI > 30kg/m2
  • Baby weighing ≥ 4.5kg in a previous pregnancy
  • Family history of diabetes (first-degree relative)
  • Family origin with a high prevalence of diabetes, for example, South Asian, black Caribbean, Middle eastern.


What are the maternal risks in a pregnancy complicated by GDM?

  • Pre-eclampsia (a condition of high blood pressure and the development of proteins in the urine during pregnancy, which in itself can give rise to complications during pregnancy)
  • Preterm labour
  • Increased monitoring and interventions during pregnancy and labour
  • Increased risk for induction of labour rather than spontaneous labour
  • Increased risk for delivery by caesarian section.


What are the risks to the baby in a pregnancy complicated by GDM?

  • Big baby (may increase the risk of trauma during childbirth and risk for induction of labour and caesarian section, rather than spontaneous labour)
  • Increased levels of amniotic fluid (may cause discomfort during pregnancy and stimulate preterm labour)
  • Stillbirth
  • Injury during birth
  • Obesity and / or diabetes later in life.


How is GDM treated?

There is a relationship between the blood sugar levels of the pregnant woman and growth of her baby. Hence, good control of the blood sugar levels is of utmost importance and will reduce the risk of having a big baby, trauma during birth, the need for induced labour and caesarian section. Maintaining good control of the maternal blood sugar levels may be done in the following ways:

  • Diet – Pregnant women with GDM are encouraged to follow a healthy diet, which is rich in proteins and avoid too much fats and carbohydrates. It is helpful that a dietician guides the pregnant woman throughout her pregnancy.
  • Exercise – Pregnant women with GDM are advised to take moderate exercise, of at least 30 minutes daily (unless there is a contraindication to exercise).
  • Oral medication – If the blood sugar levels are not controlled by diet and exercise, oral medications, known as hypoglycaemic agents, may be given to the pregnant woman. This is required in 10-20% of patients. These medications are safe both for the mother and baby.
  • Insulin – In certain instances, oral medications are not sufficient to control the blood sugar levels, so that insulin needs to be started. Insulin is a medication, which is administered as an injection, usually in the abdomen. Insulin is also a safe medication to use during pregnancy.


How are women with GDM taken care of?

Pregnant women with GDM are generally cared for by a joint team of healthcare professionals, which include an obstetrician, a diabetologist, dietician, midwives and nurses. Women are advised to monitor and document their blood sugar levels at home at different times of the day, including on waking up, before and after food, and at bedtime. This is to ensure that the adequate treatment to maintain strict control of blood sugar levels is given. Sometimes, the pregnant woman needs to stay for a few days in hospital until this goal is reached. The growth of the baby is closely monitored by serial ultrasounds throughout pregnancy. The timing and mode of delivery is planned according to the size of the baby, control of the blood sugar levels, and any other complications in pregnancy.


What are the long-term effects of GDM?

Very often, the blood glucose levels return back to normal following delivery. In fact, treatment for GDM is generally discontinued after the baby is born. The blood sugar levels will need to be checked for a few days after delivery to ensure that these have returned back to normal.

Women with GDM carry a higher risk for GDM in future pregnancies, so it is important for these women to consult their obstetrician if they are planning a future pregnancy. Also, it is advisable that they follow a healthy lifestyle. Women who were diagnosed with GDM are also at a higher risk of developing disorders of carbohydrate metabolism later on in life, outside of pregnancy. Again, these women are advised to maintain a healthy lifestyle and to perform health checks every so often.



  • Diabetes in Pregnancy: Management of Diabetes and its complications from pre- conception to the postnatal period, NICE Guideline 63, 2015.
  • Obstetrics Evidence-Based Algorithms, Pundir & Coomarasamy, 2016.


Ms Christine Zammit Zerafa is offering online consultations to the MyMama community. Book an appointment with her should you like to discuss gestational diabetes, or other issues and conditions related to your pregnancy.


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