Elevated blood glucose during pregnancy signals a significantly higher future diabetic risk

Gestational diabetes is a strong risk factor for future type 2 diabetes, even in women with normal pre-pregnancy weight, according to a study at the University of Gothenburg. The researchers call for earlier testing and better follow-up.

Gestational diabetes is a special type of diabetes that can affect pregnant women. The condition is defined as elevated blood sugar levels, without previously known diabetes. Treatment involves self-monitoring of blood sugar, advice on lifestyle habits and, if necessary, medication.

Identifying gestational diabetes is important because the disease increases the risk of complications such as preeclampsia, the need for a cesarean section and high birth weight for the baby. Those who have had gestational diabetes are also at higher risk of later developing type 2 diabetes.

In the current study, published in eClinicalMedicine, researchers now show that gestational diabetes is a strong indicator of future risk of developing type 2 diabetes, even in women with normal weight before pregnancy.

Elevated risk even with normal weight

The study is based on data from the Medical Birth Registry on just over 1.15 million first-time mothers in Sweden, who gave birth between 1987 and 2019. 16,870 women with confirmed gestational diabetes were compared with age-matched women without the diagnosis. The median follow-up period was nine years.

The results show that women with a BMI of 35 and above, i.e. severe obesity, had an almost tenfold increased risk of developing gestational diabetes compared to women with normal weight. The risk of subsequent type 2 diabetes also increased with higher BMI, but it was significantly increased even with normal weight, which the researchers describe as particularly worrying.

"Our results show that gestational diabetes functions as a kind of stress test for the body's ability to manage blood sugar, and identifies women with a greatly increased risk of future type 2 diabetes", states Jon Edqvist, PhD and affiliated to research at the University of Gothenburg, and operating room nurse at Sahlgrenska University Hospital.

More follow-up and more studies

The researchers behind the study welcome the recently updated recommendations on gestational diabetes in Sweden, where a higher proportion of pregnant women at increased risk are expected to be offered testing earlier in pregnancy, and if necessary, interventions.

Diagnostics and care of gestational diabetes have looked very different in different parts of the country. There is a need for both improved follow-up after gestational diabetes, and more studies that investigate how such follow-up affects future health and prognosis."

Annika Rosengren, Professor, University of Gothenburg