Chennai-based doctor advocates for primordial prevention of gestational diabetes

A pregnant woman checking her blood sugar level. Image used for representational purposes
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Did you know that Angelina Jolie had gestational diabetes when she was pregnant with twins in 2008? It may not be talked about very much, but gestational diabetes – high blood sugar during pregnancy – is more common than perhaps many realise.

And while it can be controlled and managed, a new chapter by Chennai-based diabetologist V. Seshiah et al for a book, ‘Labor and Delivery from a Public Health Perspective’, outlines just how crucial it is to focus on primordial prevention: preconception care and early pregnancy screening, to break the cycle of transgenerational transmission. In other words, it explains that addressing risk factors before and during pregnancy can ensure healthier futures for both mother and children.

Why is this crucial?

As the chapter, titled ‘Hope and Scope for Diabetes-Free Generations’, accepted by global publisher IntechOpen this month details, gestational diabetes mellitus (GDM) not only affects maternal and foetal health during pregnancy, but can have a cascading effect throughout the future health of both.

A woman who has had GDM is three to seven times more likely to develop type 2 diabetes later in her life: more than half of diabetic females develop this chronic condition within years or decades of their postpartum period, at most. Children of mothers with GDM are not immune too: they are more disposed to obesity, impaired glucose tolerance, and type 2 diabetes in childhood and adulthood, entrenching the cycle of metabolic disorder for generations, making this “transgenerational transmission” of metabolic disorders, the paper points out, a public health concern.

Why does this happen?

The chapter says that the causes of GDM are multifactorial, influenced by hormonal alterations and insulin synergy. Throughout pregnancy, there is improvement in insulin sensitivity during the first trimester, although insulin resistance rises in the second and third trimesters due to hormonal changes. This physiological adaptation is critical to securing sufficient nutrient supply for the developing foetus. However, in women with GDM, this insulin resistance is further amplified and results in impaired glucose tolerance and hyperglycemia.

What happens to the foetus?

The fuel-mediated teratogenesis hypothesis may have the answer: when the foetus is exposed to an excess of nutrients, this can cause changes/interfere with normal development and potentially resulting in future health problems. In the case of GDM, the chapter says, elevated glucose transport across the placenta causes the foetus to be hyperglycemic; in response, the foetal pancreas ramp up the synthesis of insulin that results in foetal hyperinsulinemia. Insulin mimics the growth factor, which stimulates excessive foetal growth and adiposity; newborns are often large for gestational age, and most of these babies have a pre-disposition to long-term metabolic disorders – eventually leading to high glucose intolerance and insulin sensitivity in adulthood.

What can be done?

The chapter details a number of measures, critical among these being first trimester postprandial blood glucose (PPBG) testing. Prevention and management strategies to bring maternal glycemia to normal before eleven weeks of gestation are also important, the chapter says, to prevent the stimulation of excessive insulin production in the foetus. Early intervention should involve medical nutrition therapy, exercise, dietary counselling and education, aimed at optimising glycemic control while ensuring adequate nutrition for both the mother and the developing foetus. And finally, in some cases, the chapter says, pharmacological interventions may be needed – metformin, it says, is considered safe and effective for treating GBM.

To ensure future populations are free of metabolic disorders including diabetes, the chapter says, it is essential we shift from an intervention paradigm to one of primordial prevention.