Gestational diabetes mellitus (GDM) is the most common complication that occurs during pregnancy. This metabolic condition results from insulin resistance during the later trimesters of pregnancy.
According to the Centers for Disease Control and Prevention (CDC), gestational diabetes affects roughly two to 10 percent of pregnancies in the United States annually.
It can occur in pregnant women with a previous history of diabetes and among those with no complications with high blood sugar (hyperglycemia).
While certain lifestyle factors increase the risk of gestational diabetes, there may also be a connection between gestational diabetes and twin gestations.
What Is Gestational Diabetes?
Unlike type 1 diabetes or type 2 diabetes, which tend to be chronic, gestational diabetes can come and go with pregnancy. Higher blood sugar levels characterize it.
Blood sugar levels are measured in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).
According to the American Diabetes Association (ADA), normal target blood sugar levels for pregnant women are as follows:
- 95 mg/dL or less before a meal
- 140 mg/dL or less one hour after a meal
- 120 mg/dL or less two hours after a meal
What Causes Gestational Diabetes?
The exact cause of gestational diabetes is still debatable among obstetric healthcare researchers. However, most experts agree that it could be linked to the prevalence of higher levels of metabolism-involved hormones during pregnancy.
These are due to common changes during normal pregnancy — placenta hormone production and weight gain. Both can contribute to insulin resistance or impact the body’s ability to keep up with glucose levels.
Insulin Resistance During Pregnancy
Insulin is an essential hormone produced by beta cells in the pancreas. Insulin resistance, or impaired insulin sensitivity, occurs when the body builds up a tolerance to this important hormone.
Insulin resistance leads to elevated glucose levels in the blood, a byproduct of metabolism, specifically the breakdown of carbohydrates. The body uses it as the main energy source for the cells.
Once glucose enters the bloodstream, it is carried into the cells with the help of insulin. Insulin also helps regulate blood glucose (blood sugar) when levels get too high. When this insulin process is interrupted during pregnancy, gestational diabetes can occur.
What Are Common Gestational Diabetes Risk Factors?
Gestational diabetes can develop in an otherwise healthy pregnancy. However, some factors can put women at an increased risk. These include a previous gestational diabetes diagnosis or a history of high birth weight (infant macrosomia).
Other common risk factors include:
Maternal Age
Maternal age is one of the top independent risk factors for gestational diabetes. In general, women 25 years or older are at a higher risk than younger women.
Obesity
Being overweight or obese can also raise the risk of developing gestational diabetes. Numerous prospective studies have shown that a body mass index (BMI) of 25 or greater greatly increases the incidence of gestational diabetes. This is why maintaining a healthy pre-pregnancy weight is so important.
Ethnicity
Certain ethnicities are prone to developing gestational diabetes. Ethnic groups with a higher incidence of gestational diabetes include:
- Hispanic or Latino Americans
- Asian Americans
- African Americans
- Alaska Natives
- American Indians
- Pacific Islanders
Family History of Diabetes
A family history of type 2 diabetes can also increase the chances of gestational diabetes. This includes immediate family members, including parents and siblings.
Other Health Conditions
Other health conditions have been linked to gestational diabetes, such as gestational hypertension (preeclampsia). Another is polycystic ovary syndrome (PCOS), a hormone disorder that can increase insulin resistance.
How gestational diabetes affects the outcomes of twin pregnancies?
While the risk factors above are commonly associated with gestational diabetes, many have wondered how gestational diabetes affects the outcomes of twin pregnancies compared to singleton pregnancies.
Fetal Growth Rates: Singleton vs. Twin Pregnancies
One area of study involves gestational diabetes’s effect on fetal growth rate. Twin pregnancies are known to have slower growth rates among the fetuses and are predisposed to fetal growth restriction and prematurity.
While it is common for gestational diabetes to accelerate fetal growth rate in singleton pregnancies, the same is not true for twin pregnancies.
According to a retrospective cohort study by the American Journal of Obstetrics and Gynecology (AJOG), gestational diabetes is less likely to be associated with an accelerated fetal growth rate. It includes having much lower preterm birth weights.
Research conclusions state the diagnostic criteria for gestational diabetes must be individualized for those with twin pregnancies, especially since low fetal growth rates can greatly increase the risks of adverse neonatal outcomes.
Twin Pregnancies Could Increase Risk of Gestational Diabetes
Some research suggests that twin pregnancies could be a risk factor for gestational diabetes. According to one perinatal study, the odds of developing gestational diabetes were higher among twin pregnancies than in singleton pregnancies.
The study examined those with normal and overweight pre-pregnancy BMI scores. However, while the chances of developing gestational diabetes were higher among twin pregnancies among these BMI groups, more conclusive research is needed.
Other Adverse Outcomes in Twin Pregnancies
Numerous meta-analysis studies have shown that gestational diabetes has adverse pregnancy outcomes and complications for singleton and twin pregnancies.
According to obstetrics research, adverse perinatal outcomes included an increased risk for cesarean delivery (c-section) and preterm birth (under 37 weeks).
Also, gestational diabetes was associated with jaundice in singleton and twin pregnancies. However, neonatal intensive care unit (NICU) admission for newborns was only associated with singleton pregnancies.
Other possible complications of gestational diabetes can include:
- Infant low blood sugar (hypoglycemia) at birth
- Postpartum type 2 diabetes for the mother
- Stillbirth
How Do I know If I Have Gestational Diabetes?
Most women receive a screening for gestational diabetes risks during early prenatal care visits. This includes evaluating BMI and body weight during early pregnancy. However, they will receive other tests during later trimesters of pregnancy; this includes non-GDM pregnancies.
The most common gestational diabetes screening test is an oral glucose tolerance test (OGTT). This test records blood sugar levels before and after drinking a sugary solution with an overnight fast.
Blood sugar levels are typically measured at different intervals, one and two hours after drinking the sugary liquid.
How Do I Manage Gestational Diabetes?
Thankfully, there are many effective ways to help manage and treat the effects of gestational diabetes. Most of these involve lifestyle changes.
Maintaining a healthy pre-pregnancy weight is the first line of defense regarding gestational diabetes. This can be managed effectively through regular exercise and a healthy diet.
Getting Daily Exercise
Regular physical activity is essential for those looking to manage gestational diabetes. Whether low-impact aerobic exercise or strength training, glucose levels deplete when we work out — the more exercise, the greater the glucose demand.
Daily exercise can help lower blood glucose levels, including walking, hiking, swimming, yoga, and more. The goal should be 30 minutes, three to five days a week.
Consult your OB/GYN or healthcare professional before starting any new exercise plan to ensure which exercises are safe for you.
Eating a Healthy Diet
Diet is another important component to help manage and treat gestational diabetes. This can help avoid unnecessary weight gain and help manage the effects diabetes.
For maintaining blood sugar, reach for complex carbs instead of simple carbs and sugars. Due to high fiber content, complex carbs are digested slower and are less likely to spike blood sugar levels. This doesn’t include refined carbs like white rice and pasta.
Processed foods full of added sugars and artificial sweeteners should be avoided, like sodas, sweetened teas, and juices.
Healthy foods include lean proteins, like chicken, fish, chicken, and legumes. Also, choose healthy fats like coconut oil, avocados, and nuts. Low-sugar fruits and non-starchy vegetables are also healthy diet staples.
Managing with Medications
Managing gestational diabetes may also involve medication intervention. Treatment plans may include insulin injections or oral medications like metformin. Healthcare providers typically prescribe these alongside other diabetes care and management strategies.
The Bottom Line
Gestational diabetes is a metabolic condition that occurs during pregnancy. This condition is characterized by insulin resistance and high blood sugar levels.
It does carry some common risk factors, like high BMI, maternal age, and a family history of diabetes. However, many wonder if there is a connection between gestational diabetes and twin pregnancies.
While research is still ongoing, some studies have shown a very close link between the two when it comes to fetal growth rate and adverse pregnancy outcomes.
Thankfully, some effective lifestyle changes can help manage and treat the effects of gestational diabetes for singleton and twin pregnancies.
References, Studies and Sources:
Gestational diabetes and fetal growth in twin compared with singleton pregnancies | AM J Obstet Gynecol | AJOG
Gestational Diabetes in Twin Versus Singleton Pregnancies | Epidemiology
Fact Checked and Editorial Process
Diabetic.org is devoted to producing expert and accurate articles and information for our readers by hiring experts, journalists, medical professionals, and our growing Diabetic.org community. We encourage you to read more about our content, editing, and fact checking methods here. This was fact checked by Camille Freking and medically reviewed by Dr. Angel Rivera.
Owner, entrepreneur, and health enthusiast.
Chris is one of the Co-Founders of Diabetic.org. An entrepreneur at heart, Chris has been building and writing in consumer health for over 10 years. In addition to Diabetic.org, Chris and his Acme Health LLC Brand Team own and operate Pharmacists.org, Multivitamin.org, PregnancyResource.org, and the USA Rx Pharmacy Discount Card powered by Pharmacists.org.
Chris has a CFA (Chartered Financial Analyst) designation and is a proud member of the American Medical Writer’s Association (AMWA), the International Society for Medical Publication Professionals (ISMPP), the National Association of Science Writers (NASW), the Council of Science Editors, the Author’s Guild, and the Editorial Freelance Association (EFA).
Our growing team of healthcare experts work everyday to create accurate and informative health content in addition to the keeping you up to date on the latest news and research.
