What is Gestational Diabetes Mellitus (GDM)?
Gestational Diabetes Mellitus is diabetes that can develop during pregnancy. It usually goes away after giving birth but may persist in some cases.
By Dr C Kamath
Consultant Diabetologist and Endocrinologist
Diagnosis of GDM is critical because of its high prevalence and the impact it may have on maternal or neonatal morbidity and mortality. Gestational Diabetes Mellitus has been identified as a potential risk factor for poor health in pregnant women.
What causes GDM?
During pregnancy, many hormones come into play, and these hormones can make it hard for the body to use insulin properly. This leads to an increased risk of insulin resistance and some women are unable to produce enough insulin to overcome this. This makes it difficult for the body to use glucose adequately for energy, resulting in high blood sugar levels. This leads to gestational diabetes.
Who is at Risk of GDM?
Women who are overweight or obese, have a previous history of GDM, have had a large baby (>4kg), a family history of diabetes mellitus and are of South Asian origin (Indians, Pakistanis, Bangladeshis, Sri-Lankans and others).
Can GDM be prevented?
The prevalence of GDM is high in India. It is difficult to guess uniform incidence levels of GDM in the country, because of differences in the racial, socioeconomic, food habits and livelihood conditions.
One cannot prevent it, but some things can be done to reduce the risk of developing it. These include managing weight, having healthy food and remaining active before pregnancy.
What are the signs or symptoms of GDM?
Many women may have no noticeable symptoms at all. As some of the signs of diabetes like feeling tired or needing to go to the toilet more often, mimic symptoms experienced during pregnancy, most cases are diagnosed during screening for gestational diabetes.
How is GDM diagnosed?
GDM is diagnosed using a test called an Oral Glucose Tolerance Test, also known as an OGTT.
The OGTT is done between 24-28 weeks of pregnancy but can be done early in pregnancy also if the woman has symptoms or risk factors. The pregnant woman is asked to consume 75grams of glucose and blood sugar levels are measured at baseline and at 2 hours.
If a woman has had GDM before, she will need the OGTT or self-monitoring of blood sugar levels at home early in pregnancy.
What are the complications associated with GDM?
High blood sugar levels if left undiagnosed or untreated during pregnancy can cause serious health issues both to the mother and her baby. GDM may increase the risk of high blood pressure and /or pre-eclampsia and Caesarean section in the mother. The baby may be at increased risk of preterm birth, excessive weight gain, breathing difficulties, low blood sugar level (hypoglycaemia) and stillbirth.
Is there a link between Gestational diabetes and Type 2 diabetes mellitus?
Having gestational diabetes increases the risk of developing it again in future pregnancies. It also increases the risk of developing type 2 diabetes after delivery or even 5-10 years later. There is also an increased risk of the child becoming overweight and going on to develop type 2 diabetes as an adult.
How is GDM Managed?
A woman diagnosed with GDM will need to check her blood sugar levels regularly using a glucometer at home. For some women, healthier dietary choices and physical activity might be enough to achieve target blood sugar levels.
However, some women might need medication including insulin to help achieve target blood sugar levels in addition to diet and physical activity.
Physical activity (after consulting your doctor) helps the body to use insulin more effectively and lowers blood sugar levels. Women with GDM should aim to include some form of physical activity like 30minutes of walking after lunch or dinner, yoga or light exercises.
There is a lot of shame and misconceptions attached to being a diabetic, and patients can be upset and in denial. Being diagnosed with GDM can also be scary and confusing, but with good management of blood sugar levels, a woman can have a healthy and successful pregnancy.
Pregnant women do not appear more likely to contract infection compared to the general population, but are more vulnerable to the severe effects of COVID-19, especially in the third trimester and are advised to stringently follow social distancing and hygiene measures.
Dr C Kamath is a Consultant Diabetologist and Endocrinologist at Diabetes and Endocrine Clinic,
Ground Floor, Vivekananda Corner, Hubballi.