Contrary to common notions, gestational diabetes also affects non-obese women. In their case, developing diabetes and metabolic syndrome five years after delivery is specifically associated with high body fat content/percentage.
In Finland, gestational diabetes is diagnosed in as many as 18% of expectant mothers. In addition to effects on both the mother and child during pregnancy, the disorder is an indication of a seven-fold risk of diabetes in the future. In the RADIEL study, focusing on the prevention of gestational diabetes through lifestyle modifications, lifestyle counselling reduced the incidence of gestational diabetes in high-risk women by 36%.
According to the doctoral dissertation by Emilia Huvinen, Licentiate of Medicine, lifestyle counselling also impacted health after childbirth. In the first year after delivery, there were 82% fewer glucose metabolism disorders in the lifestyle counselling group compared to the control group. Diabetes or a preceding glucose metabolism disorder was diagnosed in 13% of the control subjects, while the corresponding figure was 3% in the counselling group.
Women at high risk for diabetes were invited to participate in the RADIEL study (2008–2014). They had a body mass index of 30 or over and/or a prior diagnosis of gestational diabetes. Altogether 724 women were randomised already before pregnancy or in early pregnancy into counselling and control groups. Trained nurses provided individualized dietary and exercise counselling every three months before and during pregnancy, as well as six weeks and six and twelve months after delivery. Five years after delivery, the mothers and their children were invited for a follow-up visit (2013–2017).
Diverse background for gestational diabetes
Several factors underlie gestational diabetes. Contrary to popular belief, this disorder can also affect women of normal weight. In the RADIEL data, the highest incidence of gestational diabetes in the second trimester (36%) was indeed found in normal-weight women with a history of gestational diabetes, despite their being the healthiest subjects during early pregnancy in terms of metabolism.
Increased risk of diabetes and metabolic syndrome
Pregnancy is like a crystal ball that reveals a lot about the future health of the mother-to-be. Patients with gestational diabetes are at a seven-fold risk of developing type 2 diabetes in the future. RADIEL was the first study that paid particular attention to the subsequent health of women of normal weight as well. Five years after delivery, 15% of RADIEL study subjects were diagnosed with abnormal glucose metabolism, while 4% had already developed type 2 diabetes. Those of normal weight also belonged to the at-risk group.
Metabolic syndrome was diagnosed in one-third of overweight women and in 11% of those who were no more than slightly overweight before pregnancy. In these previously non-obese women, metabolic syndrome and/or a glucose metabolism disorder was diagnosed already at a significantly lower body mass index range. Despite an almost normal BMI, the body fat content exceeded the limit of obesity in more than half of the women and was connected with morbidity.
Glucose values should be monitored also after delivery
“The dissertation findings highlight the significance of glucose tolerance tests during pregnancy regardless of body weight. Without them, this high-risk group cannot be identified. Neither should women with gestational diabetes be forgotten after giving birth,” Huvinen states.
“This ‘crystal ball’ of pregnancy reveals an at-risk group with public health significance that merits regular controlling and every possible support for achieving lifestyle changes that promote health of the whole family.”
- Lifestyle counselling during and after pregnancy has a positive effect on health after childbirth.
- Non-obese women might also be at high risk for gestational diabetes.
- They are also at risk of developing diabetes and metabolic syndrome after giving birth.
- In this group, diabetes and metabolic syndrome occur already at a lower body mass index range.
- This group includes many women with a normal BMI but exceptionally high body fat percentage, which is associated with a risk of morbidity.
Contact information: Emilia.huvinen@helsinki.fi
Academic Dissertation: The heterogeneity of gestational diabetes and long-term effects of lifestyle intervention among high-risk women