Gestational diabetes refers to the type of diabetes that gets diagnosed for the first time during pregnancy, which affects the utilization of glucose by your cells, similar to other types of diabetes. Consequently, it results in elevated blood sugar levels, which can have adverse effects on your baby’s health and pregnancy.

It is widely acknowledged that gestational diabetes can escalate obstetric complications and the likelihood of the mother developing diabetes, heart disease, and dementia. Moreover, children born to mothers with gestational diabetes have a higher chance of developing obesity and hypertension as they mature.

Fortunately, there are measures you can take to manage gestational diabetes effectively.

A new Northwestern Medicine study shows that pregnant women should dim the lights in their homes and turn off or at least dim their computer or smartphone screens a few hours before bedtime to lower their risk of gestational diabetes mellitus.

In the multi-site study, women who got gestational diabetes mellitus were exposed to more light in the three hours before they went to sleep. There was no difference between individuals who developed it and those who did not in terms of their daytime or nighttime light exposure or their levels of exercise.

The findings of the study, according to lead study author Dr. Minjee Kim suggest “that light exposure before bedtime may be an under-recognized yet easily modifiable risk factor of gestational diabetes.”

There is mounting evidence linking nighttime light exposure to poor glucose control in non-pregnant people. Yet, little is known about how gestational diabetes, a frequent pregnancy condition with serious health consequences for both mother and child, is affected by exposure to evening light throughout pregnancy.

This is one of the first large-scale studies to look at the effect of being exposed to light just before bed on the likelihood of getting gestational diabetes.

The findings were just published in the American Journal of Obstetrics and Gynecology Maternal Fetal Medicine.

Gestational diabetes is becoming more common in the US and around the world. Around 4.5% of first-time pregnant women having a child born between 2011 and 2013 got gestational diabetes, with an average increase of 3.4% every three-year period between 2014 and 2019. In 2020, gestational diabetes affected 7.8% of all births in the United States.

According to data, women who have gestational diabetes are roughly ten times more likely to acquire type 2 diabetes mellitus than those who do not have glucose difficulties during pregnancy, according to Kim.

Bright light exposure before sleep may occur from bright lights in your house as well as electronics such as televisions, laptops, and cellphones.

“We don’t think about the potential harm of keeping the environment bright from the moment we wake up until we go to bed,” comments Kim. “But it should be pretty dim for several hours before we go to bed. We probably don’t need that much light for whatever we do routinely in the evening.”

Although Kim suggested that the issue may be compounded, scientists are unsure exactly which intense light source is to blame.

In the three hours before to going to bed, Kim advised trying to limit any ambient light. It’s advisable to avoid using your phone or computer during this time. Kim advised people to utilize the night light setting and turn off the blue light if they must use their devices, but to keep the displays as dark as possible.

If a woman gets gestational diabetes during her first pregnancy, she is more likely to get it again during her next pregnancy.

Pre-sleep light exposure speeds up heart rate and raises blood pressure, insulin resistance, and belly obesity.

Pre-sleep light exposure may influence glucose metabolism through sympathetic hyperactivity, which causes the heart rate to increase when it should be decreasing. 

“It seems there is inappropriate activation of the fight or flight response when it is time to rest,” Kim adds. 

Data shows that sympathetic overactivity may lead to cardiometabolic disease, which is a group of conditions that all lead to heart disease. These conditions include abdominal obesity, insulin resistance, high blood pressure, and an imbalance of lipids.

Between 2011 and 2013, the study was done on 741 pregnant women in their second trimester at eight clinical sites in the U.S. An actigraph worn on the participants’ wrists was used to measure their exposure to light. The women were measured during their second trimester of pregnancy, which is when they usually get checked for gestational diabetes.

Even after adjusting for age, BMI, race/ethnicity, education, commercial insurance, work schedule, season, sleep duration, sleep midpoint, sleep regularity index, and daytime light exposure, pre-sleep light exposure was still strongly linked to gestational diabetes.

Rising BMI and maternal age are hypothesized to contribute to the alarming rise in the prevalence of gestational diabetes.

“But even after adjusting for BMI and age, gestational diabetes is still rising,” Kim adds. “We have a lot to prove, but my personal worry is that light may be silently contributing to this problem without most people realizing the potential harm.”

Reducing the risk of gestational diabetes is possible via a number of measures, including but not limited to weight loss and regular exercise.

“Turning down the lights is an easy modification you can make,” Kim adds. 

“Now I’m the light police at home,” Kim remarks. “I see all this light I never thought about before. I try to dim the light as much as possible. Just for evening activities such as dinner and bathing the kids, you don’t need bright light.”  

“This study highlights the importance of reducing light exposure in the hours before bedtime,” remarks senior author Kathryn Reid.

Other measures include adhering to a healthy diet, engaging in physical activity, and taking medication as prescribed, if required.

By keeping your blood sugar levels under control, you can ensure the well-being of yourself and your baby, as well as avoid complications during childbirth.

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