While pregnancy is an incredible journey full of anticipation and happiness, it is crucial to understand that it can also present some unique health challenges for both mom and baby. One such risk is Gestational diabetes mellitus (GDM), a type of diabetes that may occur during pregnancy.
It is a common condition that typically arises in the second or third trimester of pregnancy and usually resolves after delivery. To ensure a healthy pregnancy, it is important for expectant mothers to be aware of GDM and understand how to manage it.
What Can Cause Gestational diabetes mellitus (GDM) During Pregnancy?
Gestational diabetes mellitus (GDM) occurs when the body cannot produce enough insulin, a hormone that regulates blood sugar levels, to meet the extra demands of pregnancy. This hormonal imbalance is caused by the placenta, which connects the mother to the baby, and produces hormones that can interfere with the mother’s insulin sensitivity.
While the exact cause of GDM is not fully understood, there are several factors that can increase the risk of developing it during pregnancy. These risk factors include:
- Overweight / Obese
- Family history of diabetes / diabetes mellitus
- Hormonal Imbalances
- History of Polycystic ovary syndrome (PCOS)
- Personal history of GDM
- Previous poor pregnancy (obstetric) outcomes that are usually associated with diabetes e.g. stillbirth
- Excessive maternal weight gain
- Excessive growth of fetus
- History of delivering big baby
- History of fetal death
Tests & Diagnosis for Gestational Diabetes
Diagnosis of Gestational Diabetes Mellitus (GDM) is crucial to ensure appropriate treatment can be given to minimise risks to the pregnancy. While the risk of GDM is higher in certain groups of women, it can occur in any pregnant woman. In Singapore, an oral glucose tolerance test (OGTT) is offered to all pregnant women between 24 and 28 weeks of pregnancy to screen for GDM.
However, if you have a history of GDM, glucose in your urine, or symptoms of diabetes, the test will be performed earlier and repeated at 24 to 28 weeks if the first test was normal.
The OGTT involves fasting overnight, a blood test for glucose in the morning, followed by a standard 75 g glucose drink, and repeat blood tests for glucose at 1 hour and 2 hours after the glucose drink. GDM is diagnosed if any one of the three blood results indicates higher than expected blood glucose levels.
While the standard glucose drink may cause some to feel nauseated, and in rare cases, trigger vomiting, there are no significant risks or side effects associated with the test. If you experience any discomfort, the test can be rescheduled for another day.
Although an oral glucose tolerance test (OGTT) is the standard screening method for gestational diabetes mellitus (GDM) in Singapore, doctors may choose not to perform the test for all patients. Instead, some doctors may opt to only perform the OGTT on patients with risk factors for GDM.
How to Manage GDM
Managing Gestational Diabetes Mellitus (GDM) usually involves making some lifestyle changes, monitoring blood sugar levels regularly and taking medication if necessary. Some ways to manage GDM include:
- Healthy Eating: Eating a balanced and nutritious diet can help regulate blood sugar levels. This involves consuming a diet that is rich in fiber, lean protein, and healthy fats. In addition, it is commonly advised to avoid consuming high sugar content foods and to consume carbohydrates in moderation. Durian, ice cream, cakes, and bubble tea should be avoided.
Women with GDM should work with a registered dietitian or healthcare provider to develop a personalised meal plan that meets their specific nutritional needs.
- Regular Physical Activity: Light exercise such as walking or swimming can help improve insulin sensitivity and lower blood sugar levels. However, it is essential to consult with a healthcare provider before starting any exercise regimen to ensure that it is safe and appropriate for the individual.
- Blood Sugar Monitoring: Blood sugar monitoring is an important part of managing Gestational Diabetes Mellitus (GDM). Doctors usually ask patients to perform blood sugar profiles, which involves checking their blood sugar levels before and after breakfast, lunch, dinner, as well as one final check before bedtime. The results of these blood sugar profiles are used to adjust the treatment plan according to the patient’s individual needs.
In addition, doctors may also measure the patient’s serum HbA1c levels to monitor their blood sugar levels over a two-month period. HbA1c levels provide an estimate of the average blood sugar level over this period, which helps doctors to identify trends and adjust the treatment plan accordingly. By monitoring blood sugar levels closely, doctors can help to ensure that GDM is managed effectively, minimising risks to the pregnancy and the mother’s health.
- Medications: In some cases, medication may be necessary to help manage blood sugar levels. This may include insulin injections or oral medications that help regulate blood sugar levels effectively.
- Regular Prenatal Care: Women with Gestational Diabetes Mellitus (GDM) should receive regular prenatal care, including frequent check-ups and fetal growth monitoring, to detect any potential complications early and ensure that both mother and baby receive appropriate care. It is crucial for women with GDM to closely follow their healthcare provider’s recommendations for managing the condition to reduce the risks to both mother and baby and ensure a healthy pregnancy and birth.
Depending on the patient’s condition, doctors may advise earlier delivery by induction or caesarean section to minimize the risk of sudden fetal demise, which is a potential complication of GDM. Therefore, receiving regular prenatal care and following the recommended guidelines for managing GDM is crucial for a healthy pregnancy and delivery.
What are the risks of GDM for the mother and the baby?
Untreated or poorly managed GDM can increase the risk of health problems for both the mother and the baby.
Some of the risks for the mother may include:
- Preeclampsia: High blood pressure during pregnancy that can damage organs, including the liver, kidneys, and brain.
- Delivery complications: GDM can increase the risk of needing a cesarean delivery, which is a surgical procedure to deliver the baby. Type 2 diabetes: Women with a history of GDM have an increased risk of developing type 2 diabetes later in life.
For the baby, GDM can increase the risks of:
- Macrosomia: A condition where the baby is larger than average, which can increase the risk of delivery complications and the need for a cesarean delivery.
- Hypoglycemia: Low blood sugar in the baby after birth, which can cause seizures or other complications if not treated promptly. Respiratory distress syndrome: Difficulty breathing due to underdeveloped lungs.
- Jaundice: A yellowing of the skin and eyes due to elevated bilirubin levels in the blood.
- Stillbirth: In rare cases, GDM can increase the risk of stillbirth.
While Gestational diabetes mellitus (GDM) can pose risks to both mother and baby, it is often possible to manage the condition effectively through personalised dietary plans and regular monitoring. By following the advice of healthcare professionals and making healthy food choices, patients with GDM can minimise the potential complications and enjoy a safe and healthy pregnancy.
Reviewed by Dr Phua Soo Mear on 25 April 2023.
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Dr Phua Soo Mear
Obstetrics & Gynaecology
Gynae Health Clinic Pte Ltd
A wholly owned subsidiary of 
Singapore Women’s & Children’s Medical Group
Blk 211 Hougang Street 21
#01-289
Singapore 530211
Tel: +65 6282 8960
Dr Phua Soo Mear is a medical specialist in Obstetrics & Gynaecology with almost 30 years of experience. Dr Phua Soo Mear graduated from National University of Singapore in 1983 with the degree of MBBS. He was awarded the Ministry of Health specialist traineeship in Obstetrics and Gynaecology in 1986. Dr Phua passed the Membership examination of the Royal College of Obstetricians & Gynaecologists in 1989. He was awarded Fellow of the Royal College of Obstetrician & Gynaecologist in 2003. Dr Phua worked in the O&G departments at the former Toa Payoh General Hospital and Kandang Kerbau Hospital from 1986 to 1992. He started the Gynae Health Clinic at Kovan in 1993.
