During which trimester is the risk for gestational diabetes highest?

The risk for gestational diabetes is highest during the third trimester. This is primarily due to the physiological changes that occur as pregnancy progresses. In the later stages of pregnancy, the body experiences increased insulin resistance, which is compounded by the hormonal changes that support fetal growth and development. These hormonal changes, produced by the placenta, contribute to a higher demand for insulin.

As a result, women who may have managed to maintain normal blood glucose levels earlier in the pregnancy may find that their bodies are unable to respond adequately to the increased insulin requirement as they reach the third trimester. Therefore, this increased insulin resistance, coupled with the changes in metabolism and the growth of the fetus, raises the risk of developing gestational diabetes during this period.

In contrast, while gestational diabetes can occasionally be detected in the first or second trimester, the prevalence and risk are significantly lower during those earlier stages compared to the third trimester, making it the period of highest concern for this condition.