Swiftly achieving glycemic control after a diagnosis of gestational diabetes can bring the baby’s risk obesity in childhood down to a level similar to that of children whose mothers did not have gestational diabetes, new research being presented at the annual meeting of the European Association for the Study of Diabetes (EASD) in Madrid, Spain (9-13 September), has found.

Gestational diabetes, a type of diabetes that can develop during pregnancy, affects 14% of pregnant women globally and is becoming more common, with those who are living with obesity, have a family history of diabetes and/or older at greater risk. Race and ethnicity can also affect risk.

It usually goes away after birth but carries a range of risks during and after pregnancy. Mothers are at high risk to develop diabetes a few years later and their children are at higher risk of premature birth, being born with a large-for-gestational-age weight and having neonatal hypoglycemia. Children are also at higher risk of cardiometabolic complications later in the life, including obesity and diabetes.

Achieving glycemic control soon after the diagnosis of gestational diabetes and maintaining it through pregnancy, up to the delivery, is associated with reduced rates of perinatal complications.”

Dr. Assiamira Ferrara, lead researcher, Director of the Center for Upstream Prevention of Adiposity and Diabetes Mellitus, Division of Research, Kaiser Permanente Northern California, Oakland, California, USA

“Treatments, which include healthy diet, exercise and blood-sugar lowering medications, aim to achieve optimal glycaemic control – keep blood sugar in the normal range – during pregnancy.”

However, the role of glycaemic control on child obesity risk has yet to be proven.

To find out more, Dr Ferrara and colleagues studied 258,064 women who gave birth in the US between 2011 and 2023 and their children.

17,316 of the women had gestational diabetes and control of their blood sugar after diagnosis was divided into four trajectories or groups: stably in the optimal range (patients who achieved optimal glycaemic control soon after diagnosis and maintained it throughout their pregnancy, 39.2%), rapidly improving to optimal (patients who achieved optimal glycaemic control within 4-6 weeks of diagnosis and maintained it throughout their pregnancy, 32.3%), slowly improving to near optimal (16.7%) and slowly improving to suboptimal (11.8%).

Childhood obesity was defined as sex-specific BMI-for-age ≥95^th percentile, based on the United States Centers for Disease Control and Prevention charts.

Obesity prevalence at 2-4 years was 15.1% in children of women without gestational diabetes, and 15.9%, 18.7%, 20.9% and 24.6% in children of women in the stably optimal, rapidly improving to optimal, slowly improving to near optimal and slowly improving to suboptimal glycaemic control groups, respectively.

Further analysis showed that the risk of childhood obesity increased with maternal blood sugar levels.

At 2-4 years, children of women with gestational diabetes in the stably optimal and rapidly improving to optimal groups had a similar risk of obesity to those whose mothers didn’t have gestational diabetes. 

Children of women with gestational diabetes in the slowly improving to near optimal and slowly improving to suboptimal groups had a higher risk of obesity (13% and 23% higher, respectively).

At 5-7 years, only children of women with gestational diabetes in stably optimal group had an obesity risk similar to that observed in children of individuals without gestational diabetes.

The children whose mothers were in the rapidly improving to optimal and slowly improving to near optimal were at 18% and 19% higher risk of childhood obesity, respectively, than those whose mothers didn’t have gestational diabetes.

For those whose mothers blood sugar was the least well controlled, the slowly improving to suboptimal group, the risk of childhood obesity was 30% higher.

The study’s authors conclude that swiftly achieving glycaemic control after diagnosis of gestational diabetes can bring the childhood obesity risk down to a level similar to that seen in children whose mothers did not have gestational diabetes.

Dr Ferrara says: “When gestational diabetes is not properly managed, this increases the baby’s risk of a high birth weight and may predispose them to obesity.”

“The good news is that if the mother’s blood sugar is quickly brought under control, her baby’s risk of childhood obesity is similar to that of children whose mothers had normal blood sugar in pregnancy.”

“Women who are diagnosed with gestational diabetes should start to follow the treatment plan drawn up by their physician as soon as possible. This is likely to initially involve dietary changes, exercise and monitoring of glucose levels. If blood sugar levels are not in the recommended range within two weeks they should start medication to lower the level, as prescribed.”

“Obesity increases the risk of developing diabetes and heart disease and once it is established, it is hard to reverse, and so anything we can do to reduce the risk of it developing is important.”