At what stage of pregnancy is the risk of gestational diabetes highest?

The risk of gestational diabetes is highest during the third trimester of pregnancy. This is primarily due to significant hormonal changes that occur as the pregnancy progresses. During the third trimester, the placenta produces increased amounts of hormones such as human placental lactogen and cortisol, which can lead to insulin resistance. As the body’s ability to use insulin effectively decreases, it can result in elevated blood glucose levels, thereby increasing the risk of developing gestational diabetes.

Additionally, during the third trimester, there is usually an increase in the woman's body weight and fat stores, which can also contribute to insulin resistance. The combination of these physiological changes makes the third trimester a critical period for monitoring and managing blood glucose levels to ensure the health of both the mother and the developing fetus. In contrast, the risk of gestational diabetes is lower during the first and second trimesters when insulin function is typically more efficient.