Published January 22, 2024
One of the most common conditions that can arise during pregnancy is gestational diabetes, and it can affect patients with no known risk factors. It currently impacts 300,000 patients in the U.S. each year and rates have increased nearly 30% over the past two decades.
Gestational diabetes is a disorder of glucose management during pregnancy, primarily driven by hormones from the placenta. These hormones are present in all pregnant patients to help get sugar from the patient’s body to their baby. However, sometimes these hormones cause blood sugar to remain high which leads to gestational diabetes.
Risk of gestational diabetes can be reduced by eating a healthy diet, not gaining excessive weight and being active in early pregnancy. Some patients may have other underlying conditions that still put them at risk. Common risk factors can include:
Patients who do not receive the appropriate treatment can develop increased risk of preeclampsia, increased risk for a cesarean delivery and increased risk for blood loss at delivery.
For the baby, it can lead to higher birth weights, trouble navigating the birth canal, increased risk of getting stuck during delivery which can lead to birth trauma and low blood sugar necessitating treatment in the special care nursery or neonatal intensive care unit (NICU).
Gestational diabetes can also have health consequences long after delivery.
“Gestational diabetes is a strong warning sign for future diabetes,” said Tulin Ozcan, MD, maternal-fetal medicine specialist with Yale New Haven Health and associate professor of Obstetrics, Gynecology and Reproductive Sciences at Yale School of Medicine. “Gestational diabetes increases the lifetime risk of developing type 2 diabetes by approximately seven to 10-fold as compared to women without gestational diabetes.”
Since a history of gestational diabetes increases the risk of diabetes long term, it is important to follow up for postpartum glucose testing and have it repeated every two to three years.
That’s why it’s so important for all patients to get screened for gestational diabetes. In the U.S. this is done between 24 and 28 weeks of gestation with a two-step test.
First patients undergo the glucose challenge test or GCT. During this test, patients must drink a sugary drink and then have their blood sugar measured one hour later. Those who fail the glucose challenge test are then asked to complete a 3-hour glucose tolerance test. During that test, patients must fast first.
Patients should not try to “pass” their glucose challenge test by fasting beforehand. That could lead to abnormal results which would then require patients to do the glucose tolerance test. Instead, patients should eat a normal, balanced meal.
Patients diagnosed with gestational diabetes meet with a diabetes nurse educator to learn about proper management. For most patients that involves checking their blood sugar levels four times a day and making modifications to their lifestyle. This can include exercising 30 minutes most days and eating balanced meals and snacks that include a mix of complex carbs, fat, and protein to keep blood sugar levels steady.
“Studies suggest that 70-85% of people with gestational diabetes can manage it with lifestyle modification alone,” said Dr. Ozcan. “However, with persistently high blood glucose levels, medication treatment is warranted with insulin as the preferred first-line agent and with metformin as an alternative.”
These medications are perfectly safe to take during pregnancy, and most patients don’t need to continue taking medication after pregnancy if their gestational diabetes resolves.
But once baby comes and gestational diabetes is no longer a concern, regular check-ups with a primary care clinician and healthy lifestyle modifications will still be important in helping to reduce long-term health impacts and the risk of gestational diabetes in a future pregnancy.
