Managing Gestational Diabetes During Pregnancy

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 factors for gestational diabetes

Common risk factors can include:

• Older maternal age
• Higher BMI
• Chronic hypertension
• Polycystic ovary syndrome (PCOS)

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.

“About 50% of patients will go ahead over the course of their life to develop type 2 diabetes and it also increases the risk for their offspring so that the baby during that pregnancy may have type 2 diabetes later in life as well,” said Yale New Haven Hospital affiliated high-risk pregnancy specialist Audrey Merriam, MD, MS, associate professor of Maternal-Fetal Medicine at Yale School of Medicine.

Testing for gestational diabetes during pregnancy

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 od 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.

Dr. Merriam says 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.

Managing gestational diabetes

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.

“In the U.S. about 80% of patients can manage their gestational diabetes just through diet and exercise management alone. For the remainder of patients, they do need some medication to help manage their diabetes and keep their blood sugars in a range that we would like to optimize outcomes for patients and their babies,” said Dr. Merriam.

Medications can include insulin or metformin, a medication that is commonly prescribed to patients with PCOS. If patients need to take a medication, Dr. Merriam says not to worry. They are perfectly safe to take during pregnancy and most patients don’t need to continue taking medication after pregnancy as 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.