Gestational Diabetes

Gestational diabetes (Pregnancy diabetes) is a condition characterized by elevated blood sugar levels that first appear during pregnancy or are diagnosed during pregnancy.

Pathogenesis

During pregnancy, hormonal changes occur in the mother’s body to support fetal development. These hormones can reduce the effectiveness of insulin, leading to elevated blood glucose levels. Normally, the pancreas compensates by increasing insulin production to maintain balance. However, in some women, the pancreas cannot meet this increased demand, resulting in elevated blood glucose. This condition is called gestational diabetes. It typically develops between the 24th and 28th weeks of pregnancy and often presents no symptoms, making regular screening tests essential for detection.

Prevalence and Risk Factors

Gestational diabetes occurs in approximately 5% to 10% of pregnancies worldwide, with rates rising to as high as 15% in certain regions. Studies in Türkiye indicate prevalence rates between 7% and 15%. This condition can pose a serious health risk to both mother and fetus, as it affects the health of both. The risk of developing gestational diabetes increases in certain circumstances. For example, women with a family history of diabetes, particularly those with a mother or father who has Type 2 diabetes, are at higher risk. Additionally, obesity or being overweight, a pre-pregnancy body mass index above 30, a previous history of delivering a large baby, hormonal disorders such as polycystic ovary syndrome, and advanced maternal age (over 35 years) all elevate the risk. Women who have had gestational diabetes in previous pregnancies are also at increased risk of recurrence.

Causes

During pregnancy, the placenta secretes various hormones to support fetal development. These include placental lactogen, progesterone, cortisol, growth hormone, and prolactin. These hormones induce insulin resistance by reducing the body’s sensitivity to insulin. Insulin resistance means the body’s cells respond less effectively to insulin, forcing the pancreas to produce more insulin to maintain normal blood glucose levels. If the pancreas cannot produce sufficient insulin, blood glucose rises, resulting in gestational diabetes. This mechanism occurs naturally in all pregnancies, but gestational diabetes develops only in women whose pancreas fails to compensate adequately. Genetic factors and environmental influences also play a role.

Symptoms

Gestational diabetes is typically asymptomatic. Therefore, glucose challenge tests and oral glucose tolerance tests are crucial for diagnosis during pregnancy. However, some women may experience the following symptoms:

• Constant and excessive thirst
• Frequent urination beyond normal levels
• Unexplained fatigue
• Sudden and intense hunger
• Blurred vision or other visual disturbances

These symptoms can sometimes be mistaken for normal pregnancy-related changes, so definitive diagnosis requires testing.

Diagnosis

The most common method for diagnosing gestational diabetes involves screening tests performed between the 24th and 28th weeks of pregnancy. In the initial step, a 50-gram glucose load is administered, and blood glucose is measured one hour later. If the result exceeds 140 mg/dL, a follow-up 100-gram oral glucose tolerance test (OGTT) is conducted. During this test, blood glucose is measured at fasting, and at one, two, and three hours after glucose ingestion. A diagnosis of gestational diabetes is made if at least two of these four measurements exceed established thresholds. Some health organizations also use a single-step 75-gram OGTT. Diagnostic criteria are defined by international and national guidelines, and regular monitoring of pregnant women is recommended.

Blood Glucose Test. (pexels)

Risks for Mother and Baby

If untreated, gestational diabetes can lead to various complications for both mother and baby. For the mother, risks include preeclampsia (pregnancy-induced hypertension), excessive weight gain, and increased likelihood of cesarean delivery. Postpartum, the mother is at high risk of developing Type 2 diabetes in later years. For the baby, complications may include high blood glucose levels, excessive fetal growth (macrosomia), birth injuries during delivery, and postnatal hypoglycemia. Additionally, respiratory problems, jaundice, and increased long-term risks of obesity and diabetes may occur.

Postpartum Follow-up

It is important to monitor whether blood glucose levels return to normal after delivery in women with gestational diabetes. Typically, a 75-gram OGTT is performed 6 to 12 weeks postpartum to assess the mother’s glucose metabolism. If the test result is normal, the mother is still considered to be in a high-risk group for developing diabetes. Therefore, regular diabetes screening every 1 to 3 years is recommended. Maintaining healthy lifestyle habits, weight control, and regular physical activity are also essential.

Disclaimer: The content in this article is provided solely for general encyclopedic informational purposes. The information here should not be used for diagnosis, treatment, or medical advice. Before making any decisions regarding health, you must consult a physician or qualified healthcare professional. The author and KÜRE Encyclopedia assume no responsibility for any consequences arising from the use of this information for diagnostic or therapeutic purposes.