Gestational Diabetes Mellitus (GDM) is a condition characterized by high blood sugar levels that develop or are first recognized during pregnancy in a woman who did not previously have diabetes. While this diagnosis often raises the question of whether the condition can resolve before delivery, GDM does not typically disappear during pregnancy. Instead, it is a highly manageable condition that requires active monitoring and intervention to ensure a healthy outcome for both mother and baby.
Why Gestational Diabetes Persists Until Birth
GDM is fundamentally linked to hormones produced by the placenta, the temporary organ that supports the growing fetus. As pregnancy progresses, the placenta releases increasing amounts of hormones, such as human placental lactogen and cortisol, which ensure the baby receives a steady supply of glucose. These hormones cause insulin resistance by powerfully blocking the action of the mother’s insulin. While this resistance is a normal physiological adjustment in late pregnancy, women with GDM cannot produce enough extra insulin to overcome this hormonal blockade. This results in glucose building up in the bloodstream, causing elevated blood sugar. Since the placenta remains until delivery, the underlying cause of GDM persists throughout the remainder of the pregnancy, often developing around the 24th to 28th week of gestation as the placenta grows larger.
Controlling Blood Sugar Through Management
While the underlying cause remains, GDM is managed to maintain blood sugar levels within a healthy range. The first line of defense involves significant dietary changes, often guided by a registered dietitian. Nutritional counseling focuses on the type, amount, and timing of carbohydrate intake to limit spikes in blood glucose after meals. This includes eating regular meals and selecting foods with a lower glycemic index, such as whole grains, which release sugar more slowly.
Physical activity is another component, as it helps the body use glucose more efficiently and increases insulin sensitivity. Safe, moderate exercise, such as brisk walking or swimming for around 150 minutes per week, is generally recommended, provided a healthcare provider approves. Exercise contributes to better glucose control and may reduce the need for medication.
Consistent blood glucose monitoring is necessary to determine if lifestyle changes are effective, requiring women to check their levels multiple times a day. If diet and exercise alone are not sufficient to keep blood sugar within target ranges, medical intervention is introduced. Oral medications, most commonly metformin, or insulin injections may be prescribed to help the body process glucose more effectively. The dosage of these medications may need to be adjusted as the pregnancy progresses and insulin resistance increases.
Immediate Resolution After Delivery
The temporary nature of GDM is confirmed immediately after delivery, as the removal of the placenta leads to a rapid reversal of insulin resistance. The source of the insulin-blocking hormones is gone, and the body’s ability to use insulin returns to normal almost immediately. Any medications used to control blood sugar during pregnancy are typically stopped right after delivery.
To confirm resolution, blood sugar is often monitored for one or two days following the birth. A more definitive postpartum screening is conducted several weeks later (usually between 6 and 13 weeks) to officially exclude persistent diabetes. This screening is performed because a small number of women may have had undiagnosed Type 2 diabetes mistaken for GDM.
Long-Term Health Outlook
Even after GDM resolves, the diagnosis indicates a higher lifetime risk of developing Type 2 Diabetes for the mother, often cited as a sevenfold increase compared to women without a history of GDM. Regular, lifelong screening for diabetes is recommended, even if the postpartum test is normal. Women with a history of GDM should have their glucose status assessed at least every one to three years.
The child also faces an increased future health risk following exposure to high glucose levels in the womb, including a greater likelihood of developing obesity and Type 2 Diabetes later in life. Both mother and child can mitigate these risks through ongoing healthy lifestyle choices, such as maintaining a healthy weight and engaging in regular physical activity.