Gestational Diabetes Mellitus (GDM)

Gestational diabetes mellitus (GDM) is a type of diabetes that develops during pregnancy, typically in the second or third trimester. It is characterized by high blood sugar levels and insulin resistance, which can affect both the mother and the fetus.

Definition and Diagnosis

GDM is defined as diabetes diagnosed for the first time during pregnancy, excluding women with pre-existing diabetes. The diagnosis of GDM is based on an oral glucose tolerance test (OGTT), which measures blood glucose levels after consuming a sugary drink. The American College of Obstetricians and Gynecologists (ACOG) recommends screening for GDM between 24 and 28 weeks of gestation.

Risk Factors

• Obesity: Women with a body mass index (BMI) of 30 or higher are at increased risk of developing GDM.
• Family history: Women with a first-degree relative (parent or sibling) with diabetes are more likely to develop GDM.
• Age: Women over 35 years old are at increased risk of developing GDM.
• Previous history of GDM: Women who have had GDM in a previous pregnancy are at increased risk of developing it again.
• Ethnicity: Women from certain ethnic groups, such as Hispanic, African American, and Asian, are at increased risk of developing GDM.

Pathophysiology

During pregnancy, the placenta produces hormones that help the fetus grow and develop. These hormones also block the action of insulin, leading to insulin resistance. In women with GDM, the pancreas is unable to produce enough insulin to overcome this resistance, resulting in high blood sugar levels.

Complications

GDM can increase the risk of complications for both the mother and the fetus, including:

• Preeclampsia: High blood pressure during pregnancy.
• Cesarean delivery: Women with GDM are more likely to require a cesarean delivery.
• Macrosomia: Excessive birth weight, which can increase the risk of complications during delivery.
• Shoulder dystocia: A complication during delivery where the baby's shoulder becomes stuck.
• Neonatal hypoglycemia: Low blood sugar in the newborn.

Treatment and Management

The goal of treatment for GDM is to maintain normal blood sugar levels, which can be achieved through:

• Dietary changes: Eating a healthy, balanced diet that is low in sugar and refined carbohydrates.
• Physical activity: Engaging in regular physical activity, such as walking or swimming.
• Insulin therapy: In some cases, insulin injections may be necessary to control blood sugar levels.
• Monitoring: Regular monitoring of blood sugar levels and fetal growth.

Postpartum Care

After delivery, women with GDM should:

• Undergo a postpartum glucose screening test to determine if diabetes has resolved.
• Be screened for type 2 diabetes every 1-3 years.
• Maintain a healthy lifestyle, including a balanced diet and regular physical activity, to reduce the risk of developing type 2 diabetes in the future.

Frequently Asked Questions (FAQs)

What is Gestational Diabetes Mellitus (GDM)?
High blood sugar condition during pregnancy.

Who is at risk for GDM?
Overweight, family history, previous GDM, or delivering large babies.

How is GDM diagnosed?
Through a glucose screening test between 24-28 weeks of pregnancy.

What are the symptoms of GDM?
Often none, but may include increased thirst and urination.

Can GDM be managed with diet and exercise?
Yes, healthy eating and physical activity can help control blood sugar.

Do women with GDM need insulin therapy?
Some may require insulin to control blood sugar levels.

How does GDM affect the baby?
Increases risk of high birth weight, premature birth, and respiratory issues.

Can GDM increase the risk of complications during delivery?
Yes, increases risk of cesarean section and other complications.

Does GDM go away after pregnancy?
Typically resolves after giving birth, but increases risk of future type 2 diabetes.

Should women with a history of GDM be screened for diabetes after pregnancy?
Yes, recommended to screen for diabetes 4-12 weeks postpartum.