Reviewed by: Michael Fuller, MD
During digestion, the human body breaks down food and turns it into smaller molecules. One such molecule is glucose, the simplest sugar and the source of the basic energy needed to sustain human life. Glucose is absorbed directly into the bloodstream after eating, but it can't enter cells – which rely on glucose to operate normally – without the help of the hormone insulin.
The pancreas, a gland located behind the stomach, is responsible for the continuous production of insulin. When levels of sugar in the bloodstream change, the pancreas responds by producing more or less insulin as needed, and ensures that metabolism is continuing safely.
During pregnancy, the placenta produces hormones which can make cells more resistant to insulin. As the placenta grows larger, the secretion of these hormones increases and makes cells even more resistant to insulin.
Usually, the pancreas responds to the changing hormones of pregnancy by producing more insulin to overcome the cells’ resistance. If the pancreas isn’t able to meet the need for increased insulin, too little glucose enters the cells and too much stays in the bloodstream. This condition is known as gestational diabetes.
Those at higher risk for gestational diabetes include women over 25; women with a family or personal history of type 2 diabetes or prediabetes; overweight women; and black, Hispanic, American Indian and Asian women (who, for unknown reasons, are diagnosed with the condition more frequently).