How Can Gestational Diabetes Be Prevented?

In the United States, it is estimated that approximately 1-2% of pregnant women have type 1 or type 2 diabetes however about 6-9% of pregnant women develop what is known as gestational diabetes mellitus. Gestational diabetes mellitus (GDM) develops in pregnant women whose pancreatic function is unable to keep up with the demands of pregnancy. In fact, pregnancy itself can lead to changes in metabolic function (specifically insulin resistance) which researchers believe is primarily mediated by the placenta secreting of “diabetogenic” hormones including growth hormone, corticotropin-releasing hormone, placental lactogen (chorionic somatomammotropin), prolactin and progesterone. These and other metabolic changes are necessary in order to ensure proper nutrient support to the growing fetus, however, in patients more susceptible to metabolic dysfunction, this may lead to gestational diabetes. The biggest concerns with gestational diabetes come from an increased risk of preeclampsia, large for gestational age (LGA) newborns, cesarean births, fetal/neonatal hypertrophic cardiomyopathy, as well as, an increased risk of the mother developing type 2 diabetes later in life. So, who is most susceptible to developing gestational diabetes and is there anything we can do to prevent it from happening? 

Women at High Risk of Gestational Diabetes

Some of the most commonly associated risk factors associated with gestational diabetes include: 

  • Personal history of impaired glucose tolerance (an hemoglobin A1c ≥5.7), impaired fasting glucose or gestational diabetes in a previous pregnancy. 

    • Having gestational diabetes in a previous pregnancy increases your risk of developing it again in your next pregnancy by 40%!

  • Family history of diabetes, especially first-degree relatives. 

    • Just because you personally have not been diagnosed with prediabetes or diabetes, doesn’t mean you aren’t at risk. 

  • Prepregnancy BMI >30 kg/m2

  • Maternal Age (>40 years of age)

  • Polycystic Ovarian Syndrome 

  • Previous birth of an infant (≥9lbs)

How to Reduce Your Risk 

Lifestyle Interventions

Although there are certain risk factors you may not be able to control including your family history or maternal age, lifestyle intervention appears to have a major impact on reducing your risk of developing gestational diabetes. In fact, a meta-analysis of randomized trials, specifically in these high risk groups, found that lifestyle interventions could reduce the risk of gestational diabetes by approximately 20 percent compared to standard of care (often pharmaceutical intervention) . Lifestyle interventions often included dietary modifications and increased exercise, ideally initiated before pregnancy and continued throughout pregnancy, appear to make the biggest impact. So whether you are currently pregnant or trying to conceive, reducing your risk of gestational diabetes starts today. 


Although Metformin has been proposed to be the medication to “prevent” gestational diabetes, especially in patients with PCOS, the data is still unclear. Although observational studies of metformin use in patients with PCOS supported metformin to prevent gestational diabetes, a randomized trial did not. In the randomized trial, researchers investigated 273 pregnancies (among which 257 patients had PCOS). The women were randomly assigned to receive either metformin (2,000mg/day) or a placebo starting in the first trimester of their pregnancy until delivery. Researchers unfortunately found no significant difference in the prevalence of gestational diabetes between the two groups. Although in this study and others, metformin was associated with a reduction in weight gained during pregnancy, the actual evidence of metformin in reducing gestational diabetes is still not very strong. 


You may have heard that taking probiotics can reduce your risk of gestational diabetes, but what does the data really say? The truth is although probiotics are a wonderful tool for a variety of conditions, researchers are not convinced probiotics reduce the risk of gestational diabetes and in fact, may find it to be actually harmful. In a meta analysis of randomized trials, probiotics did not show a clear reduction in gestational diabetes compared to placebo; however there was an association with the probiotic group and an increased risk of preeclampsia. So again, before you start taking something “natural” or over-the-counter, always make sure to consult with your doctor because even “natural” or over-the-counter supplements can be harmful, if given to the wrong person. 


Myoinositol has been of particular interest to researchers due to its ability to improve insulin resistance. It appears to have insulin-like effects on metabolic enzymes that are thought to improve insulin sensitivity. Researchers also theorized that inositol plays a role in glycemic control because, in states of insulin resistance, like gestational diabetes and polycystic ovary syndrome, there was an increase in urinary excretion of inositol metabolites. Myoinositol is a component of the membranes of all living cells and can also be found in dietary sources especially fresh citrus fruits (except lemons), vegetables, and nuts and seeds. Although there are difference chemical isomers of inositol, (most commonly talked about D-chiro inositol and myoinositol), researchers have found that myoinositol was specifically beneficial in the reduction of gestational diabetes, where as the combination of myoinositol and D- chiro inositol may not be sufficient in the prevention of gestational diabetes. 

About the Author: Meet Dr. ZenAlissia Zenhausern- Pfeiffer, NMD, FABNE, (commonly known by her patients as Dr. Zen), is a licensed naturopathic doctor board certified in naturopathic endocrinology and the founder of NMD Wellness of Scottsdale, a premier naturopathic medical practice that focuses on helping women to take a proactive approach to their hormone and fertility health. Dr. Zen has been featured as a lead expert in Forbes, Shape Magazine, and Instyle and is deeply passionate about bridging the gap between traditional and natural medicine in the world of fertility. She works with a variety of hormone related issues including PCOS, endometriosis and unexplained infertility. Her goal is to help more women get back into the driver’s seat of their own health to make lasting transformational changes to their health to bring more cute and adorable babies into this world. Read More About Dr. Zen...