Updated: Mar 17
There’s a specific name dedicated for developing diabetes during pregnancy: gestational diabetes mellitus (GDM). Managing GDM properly is of paramount importance to ensure the optimal health of both the mother and baby.
Gestational diabetes mellitus (GDM)
Gestational diabetes is high blood sugar that develops during pregnancy and usually disappears after giving birth. It can happen at any stage of pregnancy, but is more common in the second or third trimester.
It happens when your body cannot produce enough insulin – a hormone that helps control blood sugar levels – to meet your extra needs in pregnancy.
Gestational diabetes can cause problems for you and your baby during pregnancy and after birth. But the risks can be reduced if the condition is detected early and well managed.
For women who already have diabetes before conceiving is not classified as GDM. Nevertheless, there is little difference between the treatment plans for GDM and pre-existing diabetes in pregnant women.
You may be familiar with the finger prick test for diabetic patients, which can be carried out on your own or at any community pharmacy. However, the screening test of diabetes in pregnancy is different.
The screening test of diabetes in pregnancy is called the oral glucose tolerance test (OGTT). You will be asked to drink a glucose solution and have your blood sugar level measured before and at intervals (usually 2 hours) after the glucose drink is taken. This is done to see how your body is dealing with the glucose you drank earlier. Your doctor will diagnose if you have GDM based on the test results.
During pregnancy, you can still monitor your own blood glucose using HbA1c test (which is done by pricking your finger tip for blood). Nonetheless, it is not the gold standard for diagnosing diabetes in pregnancy and current scientific evidence still advocates OGTT as the most accurate method for pregnant women.
You may consult your doctor on the best way to monitor your blood sugar during pregnancy.
Upon seeing a doctor after conception, your doctor would recommend an OGTT to you if you are eligible for any of the following criteria
Your body mass index (BMI) exceeds 27kg/m2
You had GDM in previous pregnancy
You have a first degree relative with diabetes
You gave birth to baby with birth weight >4kg previously (this is known as macrosomia)
You have a bad obstetric history (your doctor would ask you relevant questions to arrive a conclusion on this)
Your urine test showed blood sugar (glycosuria ≥ +2) on two occasions
You currently have other obstetric health issues, such as high blood pressure (hypertension), pregnancy-induced hypertension, polyhydramnios and current use of corticosteroids
These are some of the health issues that may put you at risk for developing diabetes in pregnancy, hence OGTT should be commenced as early as possible. If the first OGTT test is normal, you will be offered another OGTT at 24-28 weeks of pregnancy.
If you do not have any of the issues mentioned above and aged 25 years old and above, your doctor may recommend OGTT to you at 24-28 weeks of pregnancy.
How diabetes in pregnancy may harm you and your baby
Most women with GDM have otherwise normal pregnancies with healthy babies. However, if the diabetes is poorly managed, the following health problems may occur:
your baby growing larger than usual (known as macrosomia) – this may lead to difficulties during the delivery and increases the likelihood of needing induced labour or a caesarean section
polyhydramnios – too much amniotic fluid (the fluid that surrounds the baby) in the womb, which can cause premature labour or problems at delivery
premature birth – giving birth before the 37th week of pregnancy
pre-eclampsia – a condition that causes high blood pressure during pregnancy and can lead to pregnancy complications if not treated
your baby developing low blood sugar or yellowing of the skin and eyes (jaundice) after he or she is born, which may require treatment in hospital
the loss of your baby (stillbirth) – though this is rare
In the long run, GDM can even extend its health risks beyond the pregnancy and neonatal period. GDM is a strong marker for development of type 2 diabetes in the mother, including diabetes-related vascular disease. GDM also increases the child’s risk for developing obesity, impaired glucose tolerance, and diabetes when growing up. Some scientific evidence, although circumstantial and poor in quality, suggests that poorly controlled diabetes in mothers can affect the language development in the child.
After you are diagnosed with GDM, your doctor may prescribe you with the following arrangements:
Modification in diet and exercise, which include eating a healthy diet and staying physically active. This modification will be carried out by a professional and multidisciplinary medical team to devise a plan that is safe for you and your baby. Do not try any weight loss or ‘healthy diet’ plan before consulting your doctor first.
If you do not meet your blood sugar target within 1-2 weeks of modifying your diet and exercise, you will be offered a anti-diabetic medication called metformin. Metformin is generally safe for pregnancy, except in special circumstances which your doctor would identify for you.
If both change in diet and exercise as well as metformin are inadequate to bring your blood sugar down, your doctor may prescribe insulin injection therapy to you.
If you have pre-existing diabetes before pregnancy, you may be offered low dose aspirin supplementation (75 -150mg daily) from 12 weeks of pregnancy until term.
Follow your doctor’s suggestion in monitoring your own blood sugar using a finger prick device.
It is very important to attend follow-up with your doctor as planned, and take the medications as prescribed by your doctor. Attend your health check-ups and screening test as directed. Your dedication in following through the treatment plan will be worthwhile when you give birth to a healthy baby despite having diabetes.
UpToDate - Gestational diabetes mellitus: Obstetric issues and management.
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