Gestational diabetes is a condition marked by high blood sugar and abnormal glucose tolerance during pregnancy; it typically occurs in the second or third trimester and resolves after delivery. Early detection and management are crucial to reduce both short-term and long-term health risks for the parent and baby.

The main signs and symptoms of gestational diabetes include fatigue, nausea, increased thirst, and urination, which are often overlooked during pregnancy. High blood sugar levels, which are detected through blood tests such as glycated hemoglobin (HbA1c), are key indicators of the condition.

Gestational diabetes is diagnosed through screening at 24 to 28 weeks of gestation, typically using a 1-step or 2-step approach that involves an oral glucose tolerance test. High blood sugar levels during this test indicate gestational diabetes, and individuals who are at higher risk may be screened earlier to detect pregestational diabetes.

The primary treatment for gestational diabetes is lifestyle change, which includes medical nutrition therapy, regular physical activity, and weight management counseling, along with blood glucose monitoring. If these measures are insufficient, insulin may be prescribed, and other medications like metformin and sulfonylureas may be considered, though their safety for the fetus requires further investigation.

Several supplements — including vitamin D, polyphenols, probiotics, myo-inositol, and fish oil — have been studied for their effects on gestational diabetes. Although vitamin D and myo-inositol may reduce the risk, there is no strong evidence to support the use of supplements in treating gestational diabetes.

Diet plays a crucial role in managing gestational diabetes through individualized medical nutrition therapy, which helps maintain normal blood glucose levels. Additionally, a healthy dietary pattern that is rich in fruits, vegetables, whole grains, and fish may reduce the risk of developing gestational diabetes.

Regular exercise during pregnancy can help lower blood glucose levels and may decrease the need for medications to treat gestational diabetes, as well as reduce the risk of developing the condition. However, a clinical evaluation is advised before starting any exercise program.

Gestational diabetes is caused by a combination of genetic factors and environmental triggers (such as advanced age, diet, and obesity), which lead to insulin resistance during pregnancy. The placenta's hormone secretion can make the body less responsive to insulin, and if the pancreas cannot produce enough insulin to counteract this resistance, blood sugar levels rise, resulting in gestational diabetes.