MyFamilyDoctor, by one of the best Diabetologist in Kochi, Causes of gestational diabetes During pregnancy, the placenta produces hormones to sustain your pregnancy. These hormones make your cells more resistant to insulin. Normally, your pancreas responds by producing enough extra insulin to overcome this resistance. But sometimes your pancreas can’t keep up. When this happens, too little glucose gets into your cells and too much stays in your blood, resulting in gestational diabetes.