Gestational diabetes (GD) is a form of diabetes that emerges during pregnancy in individuals who did not have diabetes previously. This condition arises when the body struggles to effectively use or produce enough insulin, leading to elevated blood sugar levels. While gestational diabetes typically does not resolve during the third trimester, it usually disappears after childbirth. Throughout pregnancy, careful management of blood sugar levels is necessary.
Understanding Gestational Diabetes Progression
Gestational diabetes persists or can even worsen as pregnancy advances into the third trimester. This is due to the increasing influence of placental hormones, such as human placental lactogen, cortisol, and progesterone. These hormones are produced by the placenta to support fetal growth but also contribute to insulin resistance in the mother’s body, meaning her cells become less responsive to insulin. The placenta secretes hormones that elevate maternal blood glucose levels to ensure nutrient supply for the developing fetus, but these also intensify insulin resistance.
As the pregnancy progresses, the placenta grows, and the production of these hormones increases, intensifying insulin resistance. The body’s demand for insulin significantly rises to overcome this resistance. In women with gestational diabetes, the pancreas is unable to produce the additional insulin required to meet this heightened demand, resulting in persistently high blood sugar levels.
Risks and Complications
Uncontrolled gestational diabetes during the third trimester can lead to several complications for both the mother and the baby. For the baby, a primary concern is macrosomia, a birth weight larger than average. This can increase the risk of birth injuries, such as shoulder dystocia. Babies born to mothers with uncontrolled GD may also experience hypoglycemia shortly after birth, and have a higher risk of developing respiratory distress syndrome. There is also an increased long-term risk for these children to develop obesity and type 2 diabetes later in life.
For the mother, uncontrolled gestational diabetes increases the risk of preeclampsia, a condition of high blood pressure during pregnancy. It also raises the likelihood of needing a Cesarean section (C-section) due to the baby’s large size. Women who experience gestational diabetes have an increased risk of developing type 2 diabetes in the years following pregnancy.
Managing Gestational Diabetes Through the Third Trimester
Effective management of gestational diabetes during the third trimester involves a multi-faceted approach to maintain blood sugar levels within a healthy range. Dietary modifications focus on balanced meals with controlled carbohydrate intake and regular eating times to prevent spikes in blood glucose. Distributing carbohydrate intake throughout the day in smaller, more frequent meals can help stabilize blood sugar.
Regular, moderate physical activity, tailored to pregnancy, is also beneficial. Exercise helps the body use glucose more efficiently and can improve insulin sensitivity. Activities such as walking, swimming, or prenatal yoga are often recommended. Consistent self-monitoring of blood glucose levels is important to track how diet and activity affect blood sugar and to guide treatment adjustments.
If lifestyle changes alone are not sufficient to manage blood sugar levels, healthcare providers may prescribe medication. This can include oral medications or insulin injections, which are safe for use during pregnancy. These medications help the body regulate glucose levels when the pancreas cannot produce enough insulin naturally. Frequent prenatal appointments are also important to monitor both the mother’s blood sugar control and the baby’s growth and well-being.
Post-Delivery Resolution and Future Risk
Gestational diabetes resolves shortly after delivery, once the placenta is delivered. The removal of the placenta leads to a rapid decrease in the placental hormones that caused insulin resistance during pregnancy, allowing the mother’s blood sugar levels to return to normal. Post-delivery blood glucose testing is performed to confirm that the condition has resolved.
Despite the resolution after birth, mothers who have experienced gestational diabetes face an increased long-term risk of developing type 2 diabetes later in life. This risk can be as high as 50% within 5 to 10 years after pregnancy. For this reason, ongoing monitoring is recommended, with a glucose tolerance test every one to three years. Adopting and maintaining a healthy lifestyle, including a balanced diet and regular physical activity, is important to mitigate this future risk.