Gestational diabetes (GD) is a condition where high blood sugar levels develop during pregnancy in individuals who did not have diabetes beforehand. While many women manage GD with diet and exercise, some require insulin therapy to maintain healthy blood sugar levels, benefiting both mother and baby. This therapy is a common aspect of GD management, aiming for a healthy outcome.
The Role of Insulin in Managing Gestational Diabetes
Gestational diabetes stems from physiological changes during pregnancy. From 20 to 24 weeks, the placenta produces hormones like human placental lactogen (hPL), estrogen, progesterone, and cortisol. These hormones support fetal growth but can cause insulin resistance, making the body’s insulin less efficient at moving glucose into cells and leading to elevated blood sugar.
When the pancreas cannot produce enough insulin to overcome this resistance, GD develops. Requiring insulin for GD is a common physiological response to pregnancy’s hormonal demands. Insulin therapy is an effective method for lowering high blood sugar when diet and lifestyle changes are insufficient. Its objective is to prevent complications like macrosomia (excessively large baby) or newborn hypoglycemia.
Administering Insulin Safely and Effectively
Insulin is administered via injections into the subcutaneous tissue (the fatty layer beneath the skin), not muscle. Common injection sites include the abdomen, thighs, and upper arms. Rotating sites prevents lipohypertrophy (fatty lumps from repeated injections), which can interfere with insulin absorption and cause erratic blood sugar.
Insulin is delivered using pre-filled pens or vials with syringes. Pens are often disposable and convenient. Different types of insulin manage blood sugar throughout the day.
Rapid-acting insulins (e.g., aspart, lispro) work within 5-15 minutes, taken before meals for post-meal spikes. Long-acting insulins (e.g., glargine, detemir) provide a steady, background level of insulin for up to 24 hours or longer, often taken once or twice daily for overnight control. Unopened insulin should be refrigerated; opened vials or pens can be kept at room temperature for about 28 days.
Monitoring and Dosage Adjustments
Regular blood glucose monitoring is fundamental to managing gestational diabetes with insulin. Patients check levels several times daily: upon waking (fasting) and one or two hours after each main meal. Healthcare providers provide specific target ranges, such as less than 95 mg/dL (5.3 mmol/L) for fasting glucose and less than 140 mg/dL (7.8 mmol/L) one hour after a meal. These measurements provide valuable information on how the body responds to insulin and dietary choices.
Recognize symptoms of both hypoglycemia (low blood sugar) and hyperglycemia (high blood sugar). Hypoglycemia (blood glucose below 60-80 mg/dL or 4.0 mmol/L) can cause sweating, shaking, weakness, and hunger. If symptoms occur, test blood sugar immediately and treat with 15 grams of fast-acting carbohydrates (e.g., fruit juice, glucose tablets).
Hyperglycemia may cause increased thirst, frequent urination, or tiredness. Insulin doses are not fixed and require adjustment throughout pregnancy as hormonal influences change and resistance increases. Communicate closely with the healthcare team to report readings and modify doses.
Insulin’s Impact on Pregnancy and Postpartum
Expectant mothers often have concerns about medication safety during pregnancy. Human insulin does not cross the placenta, making it a safe option for managing blood sugar levels without directly affecting the developing baby. The baby’s own pancreas produces insulin in response to the glucose it receives from the mother. While high maternal glucose levels can lead to increased fetal insulin production and complications like macrosomia, the insulin administered to the mother does not directly contribute to the baby’s insulin levels.
During labor and delivery, insulin needs often decrease significantly. Once the placenta is delivered, the primary source of hormones causing insulin resistance is removed, leading to a drop in insulin requirements. Most women no longer require insulin immediately after giving birth. Postpartum follow-up includes a glucose tolerance test 4 to 12 weeks after delivery to assess for the return to normal blood sugar levels. Having gestational diabetes increases the risk of developing type 2 diabetes later in life.