Gestational diabetes is diabetes that develops explicitly during pregnancy. Gestational diabetes can be caused by existing insulin resistance and increased insulin resistance linked to hormonal changes and fat gain during pregnancy.

A​bout 6-9% of women develop gestational diabetes during pregnancy. Doctors in the U.S. may recommend testing for gestational diabetes about 6 months into the pregnancy because this is when gestational diabetes is most likely to develop.

After the pregnancy is over, blood sugar levels typically return to a healthy range. However, for those who have had gestational diabetes, there is a greater risk of developing type 2 diabetes later in life.

Dr. Wiyatta Freeman, an obstetrics and gynecology specialist at UT Physicians Women’s Center and Memorial Hermann Southeast Hospital in Houston, Texas, not involved in the study, told MNT that a history of gestational diabetes “is predictive of an increased risk of developing type 2 diabetes, metabolic syndrome, cardiovascular disease (CVD), and even type 1 diabetes.”

Therefore, individuals who’ve had gestational diabetes should schedule regular follow-ups with their physician to screen for the development of type 2 diabetes and other chronic conditions.

Dr. Kay Lovig, an endocrinologist with White Plains Hospital Physicians Associates in New York, not involved in the study, explained to Medical News Today:

“Gestational diabetes is diabetes that occurs during pregnancy. During pregnancy, hormones that are made by the placenta result in insulin resistance in everyone. Insulin resistance means that your body does not respond as efficiently to the insulin you are producing in order to have a normal blood sugar…People who develop gestational diabetes have an increase in insulin resistance as compared to someone who does not develop gestational diabetes. Therefore, those who experience gestational diabetes are at a higher lifetime risk of developing type 2 diabetes, which is also a result of insulin resistance.”

Researchers are still looking into how to best reduce the risk for type 2 diabetes among those who have had gestational diabetes.

T​his particular study looked at five modifiable risk factors among women who had a history of gestational diabetes:

1. not being overweight or obese
2. eating a high quality diet
3. exercising regularly
4. drinking moderate amounts of alcohol
5. not smoking

The study included over 4,000 participants from the Nurses’ Health Study II. Researchers followed up with participants for an average of almost 28 years. During this follow-up timeframe, 924 participants developed type 2 diabetes.

T​hey found that participants with optimal levels in all five categories had over 90% less risk of developing type 2 diabetes.

They found that “each additional optimal modifiable factor was associated with an incrementally lower risk of type 2 diabetes.”

The risk association held true, even among women who were overweight or obese or had a greater genetic risk for developing type 2 diabetes.

Sherry Roberts, registered dietitian nutritionist and certified diabetes care and education specialist, who was not involved in the research, shared her thoughts on the study to MNT:

“I feel that the study was well done and thorough as it followed nurses that had gestational diabetes for nearly 28 years. It looked at the modifiable risk factors of not being overweight or obese, high-quality diet, regular exercise, moderate alcohol consumption, and no smoking. The overall results indicate that the women that were able to maintain optimal levels of the modifications have a lower risk for developing diabetes. The clinical implications for this study provide additional support for the importance of maintaining healthy habits in order to prevent type 2 diabetes. It also demonstrates how important it is to offer prevention programs and support to those trying to prevent type 2 diabetes.”

The study did have some limitations. For example, it was an observational study, so the results cannot determine the cause. Researchers relied on participant self-reporting, increasing a certain risk for error.

The authors excluded non-white participants who were likely to have been mostly of European ancestry, which can limit how applicable the data is to other ethnic groups. It also indicates the need for more diverse cohorts for longitudinal studies in the future.

The study also specifically looked at physical activity based on leisure time activities. The researchers note that further data could look at how other physical activities, such as work-related activity, could be investigated more in the future.

They also did not have data on the severity of participants’ gestational diabetes or their baseline for blood sugar control.

Finally, based on the data collection methods and the participants, the full benefit of these healthy lifestyle choices may be underestimated. Overall, the results demonstrate the importance of maintaining a healthy lifestyle, particularly among those with a higher risk of developing type 2 diabetes.

Roberts noted the following areas for continued research:

“Additional research should be done for women with gestational diabetes that do not have a healthcare background and are part of the general population. Similar research should also be done on the children that were born to mothers with gestational diabetes.”