CGM Proves a Vital Tool in Healthy Pregnancy


While we hear a lot about the complications of type 1 diabetes in daily life, we arguably hear, read and talk less about the risks posed by type 1 diabetes (T1D) to those in specific life states. Consider pregnancy. It’s hard enough to manage one’s own body, so imagine for a moment the physical strain of building another life while also battling T1D. And what about the myriad risks faced by newborns of type 1 moms?

The results of a recent international study showed that using a continuous glucose monitor (CGM) system, as opposed to just a blood glucose meter (BGM), during pregnancy significantly benefited both mothers with type 1 diabetes and their newborns after birth.

“We hope that these results will help people with type 1 diabetes to be confident in their decision to have children and help them make informed choices with their doctors about care,” said Derek Rapp, CEO and president of non-profit JDRF, who funded the study.

The study aimed to keep blood sugars in the range of 3.5-7.8 mmol/L63-140 mg/dl—a tall order at any time, really, let alone during pregnancy. Expecting moms wearing a CGM spent an extra 100 minutes a day in the target blood glucose level (BGL) range. They also spent 72 fewer minutes a day over 7.8 mmol/L140 mg/dl. Blood sugar spikes are unhealthy for a baby in utero, and the study showed that CGM monitoring allowed the wearers catch and correct highs much more quickly.

A relatively minor 0.2 percent A1C reduction was reported between CGM users and BGM-only users. It should be noted that the study was limited to T1D patients with A1Cs well under control and less than 7 percent to start with.

The study was executed in 31 hospitals in Canada, Ireland, Italy, Spain, the United Kingdom and the United States. It included 325 pregnant women between the ages of 18 and 40 who managed their T1D with daily insulin therapy (insulin pumps or multiple daily injections). Half the women were randomly assigned to use a CGM device. The other half used fingerstick tests and a BGM four to eight times per day to measure BGLs. The study was over 24 weeks, starting between gestation weeks 10 to 12 and running through the end of pregnancy.

The study represents the first evidence to support the use of CGM systems as more beneficial during pregnancy, offering pregnant women, partners, families and those with type 1 diabetes considering pregnancy both hope and potentially key information to consider when determining T1D treatment means during pregnancy.

A second key finding of the study was the substantial decrease in complications among newborns in the CGM group.

The number of babies being born larger than average fell from 69 to 53 percent. The number of babies admitted to intensive care for more than 24 hours after birth dropped from 43 to 27 percent. Babies born with low blood sugar levels decreased from 28 to 15 percent. Furthermore, on average, babies born to CGM moms left the hospital one day earlier and had half as many neonatal care admission.

Pregnant women with type 1 diabetes are considered a high-risk group because of the demands on the body of both gestation and type 1. The conventional treatment has mostly included a closer system of monitoring before, during and after pregnancy. Among the recommendations: stepped-up visits to one’s endocrinologist for pre-pregnancy consultations, sustained maintenance of recommended BGLs for pregnancy (A1C less than 7), eye doctor visits and healthier eating and a regiment of prenatal vitamins.

The hope is that now, with the results of the study, physicians around the globe will call for the use of CGM systems during pregnancy as well.

Historically, one in two babies born to mothers with type 1 diabetes have complications related to high blood sugar. Some complications are more threatening than others. While diabetes care, treatment and technology have improved markedly over the last generation, the statistics around post-birth complications have not. Until, perhaps, now.

“Women need to manage blood glucose levels very tightly in order to avoid pregnancy complications for their babies, but that can be very difficult to do,” Dr. Denice Feig, co-principal investigator of the study, said in a press release. “We have shown here, for the first time, that using continuous glucose monitoring leads to improved blood glucose control during pregnancy and a reduction in neonatal health complications.”

Learn more pregnancy hacks with Type 1.

WRITTEN BY Greg Brown , POSTED 10/24/17, UPDATED 10/18/22

Greg Brown is a freelance writer living in the mountains of western Maine. He has written for Consumer Reports Magazine, Consumer Reports Online, The New York Times and the Chicago Tribune, among other publications. He can be found online at: