Written on December 20, 2023 by Amy Harris, MS, RN, CNM. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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The most common metabolic complication of pregnancy, gestational diabetes, affects an increasing number of pregnancies with each passing decade. Gestational diabetes poses risks to both birthing parents and their offspring. Babies born to birthing parents with gestational diabetes are at higher risk of having obesity and diabetes themselves. Given these trends, you are not alone in wondering whether gestational diabetes is genetic.
Gestational diabetes is a particular type of diabetes that occurs in pregnant people who did not have diabetes before pregnancy. Diabetes is when too much sugar (which your body stores as glucose) stays in the blood instead of being used for energy.
Gestational diabetes is one of the most common problems seen in pregnancy, impacting between 12 and 18 of every 100 pregnancies. Healthcare providers are diagnosing gestational diabetes more frequently than they did 10 years ago. Some of the explanations for why gestational diabetes impacts more pregnancies today are :
While most women with gestational diabetes are no longer diabetic after they deliver their baby, they are 10 times more likely to develop type 2 diabetes later in life. Learning to monitor your blood sugar levels (blood glucose), following a healthy diet, and regularly engaging in physical activity are all ways to reduce your risk of developing type 2 diabetes if you have had gestational diabetes.
No, not entirely. When a disease or condition is genetic, it can be passed down or inherited from birth parents to their offspring. The answer to whether or not gestational diabetes is genetic is complicated for several reasons.
First, scientists who study genes (geneticists) are just beginning to identify possible genes responsible for type 2 diabetes. They have not yet identified a single gene controlling whether or not a person will have diabetes in pregnancy. However, they have seen some similarities between the genes that predispose people to type 2 diabetes and those in people with gestational diabetes.[5-6]
Second, researchers believe that whether or not someone develops gestational diabetes may be decided by a combination of [1, 5-6]:
Epigenetic factors are environmental and behavioral factors that may alter how your genes work.
Thirdly, the relationship between pregnancy and gestational diabetes is complicated by the fact that not everyone who has gestational diabetes has it in subsequent pregnancies. It is not a simple cause-and-effect type of relationship. Similarly, while people who have had gestational diabetes are ten times as likely to develop type 2 diabetes later in life, not everyone does.
Researchers are still trying to fully understand how completely genes control whether or not someone has gestational diabetes.
There is no way to predict which birthing people will develop gestational diabetes in pregnancy. We do know that if you have gestational diabetes in one pregnancy, you may have it again in a later pregnancy. The disease has a 30% to 70% chance of recurring in subsequent pregnancies.
Researchers have also been able to identify some common traits in birthing parents who do have gestational diabetes. These are :
So, while you can’t change your genes (to whatever extent they might predispose you to gestational diabetes), you can try to maintain a healthy weight, stay physically active, and follow a nutritionally complete diet. Learn more about pregnancy and obesity >>
An HbA1c or glycosylated hemoglobin test measures your average blood sugar levels for the previous three months. The HbA1c test can provide helpful information about your blood sugar levels before conception. However, it is not the preferred laboratory test for monitoring blood glucose levels once you are pregnant.
During pregnancy, your red blood cells (which contain hemoglobin) turn over more quickly than every three months and can falsely lower HbA1c levels. Also, HbA1c is more like a 2-hour-long movie of a three-month window of time, not a snapshot of your blood sugar levels at a single point in time. Pregnancy causes the body’s need for energy to change rapidly, so blood sugar levels can quickly change.[4,10]
During pregnancy, blood sugar levels vary significantly from week to week. Even short-term fluctuations can harm the pregnant person or baby. More accurate tests are needed to check pregnant people’s blood sugar.
The tests used to diagnose gestational diabetes are either a glucose challenge test or an oral glucose tolerance test. The oral glucose tolerance test consists of fasting 8 hours before your blood is drawn, then drinking a sugary drink (the glucose challenge), waiting 2 hours, and then having your blood drawn again. The test examines your body’s ability to process sugar (glucose) over time.
These tests are usually completed between 24-28 weeks of pregnancy, although if you have other risk factors for gestational diabetes, your pregnancy care provider may screen you earlier in pregnancy. Gestational diabetes usually shows up in the middle of pregnancy.[9,12]
Even as we get closer to understanding the genes behind gestational diabetes, modern medicine does not yet know how to prevent you from getting gestational diabetes. It is known that having diabetes can impact your fertility.
We know that having blood sugar levels that are too high (called hyperglycemia) at the time of conception and in the first trimester can put pregnancies at risk. Having higher than normal HbA1C levels is associated with :
Yet, there are no standard recommendations for checking your blood sugar before trying to conceive if you do not have diabetes.[4,9,11] Nevertheless, if you have risk factors for gestational diabetes or PCOS, or if your healthcare provider has diagnosed you with prediabetes, you may want to pay closer attention to your blood sugar levels before trying to conceive.
Fortunately, a convenient, at-home HbA1C test available through Everlywell can give you an idea of your average blood sugar levels for the prior three months. By monitoring your HbA1C, maintaining a healthy weight, exercising, and eating a balanced diet, you may be able to reduce the risk of future pregnancy health issues.
Amy Harris, MS, RN, CNM has a master's degree in Maternal and Child Health from Harvard T. Chan School of Public Health. She attended Yale School of Nursing and Boston University School of Public Health to become a certified nurse midwife (CNM). She has worked for over 20 years in clinical and public health practice. She specializes in women's reproductive health care, healthy literacy, and writing about health and wellness.