Pathophysiology of gestational diabetes

The hallmark of GDM is increased insulin resistance. Pregnancy hormones and other factors are thought to interfere with the action of insulin as it binds to the insulin receptor.Placental hormones, and to a lesser extent increased fat deposits during pregnancy, seem to mediate insulin resistance during pregnancy. Cortisol and progesterone are the main culprits, but human placental lactogen, prolactin and estradiol contribute too.

Risk factors for gestational diabetes

* a previous diagnosis of gestational diabetes or prediabetes, impaired glucose tolerance, or impaired fasting glycaemia
* a family history revealing a first degree relative with type 2 diabetes
* maternal age - a woman's risk factor increases as she gets older (especially for women over 35 years of age)
* ethnic background
* being overweight, obese or severely obese increases the risk by a factor
* a previous pregnancy which resulted in a child with a high birth weight
* previous poor obstetric history