Pathophysiology of Gestational Diabetes?

QUESTION: Could you guys help me with the pathophysiology of gestational diabetes?

My physiology prof asked to prepare an essay as homework on what's going on during gestational diabetes.

As it something related to placenta, what are the hormones and stimuli given to cause insulin resistance?

Is the insulin really not released or it's just alteration in its function? Is there something related to genetics? If yes, how?

Does the baby count the same problems as the mother, in simple words, does the baby suffer from insulin resistance or it is only related to the glucose levels within mother's blood circulation?


ANSWER: Hi there,

This is a very complicated topic and I have to tell you that not all things are discovered yet. However, now I will answer to all your questions.

1. First of all, gestational diabetes is related to the placenta, because during the embryonic development the placenta produces certain hormones like progesterone, estrogen and others.

Besides this, placenta stimulates the production of other hormones like cortisol and others. These hormones, mentioned above, are stimulating the hyperplasia of the pancreatic beta-cell, which are producing insulin.

However, these hormones are causing insulin resistance too, which characterizes the gestational diabetes.

You have to know that insulin is produced and excreted from the beta- cell of the pancreas, but it is not able to estimate its effect.

Other important thing is that the insulin resistance by itself stimulates the hyperplasia of the beta cells of the pancreas, which leads to even greater insulin secretion.

2. Second thing is that the scientists suspect some kind of genetic predisposition, but this is not clear.

However, there are so called guilty-genes and the most important of them are HLA DR3 and HLA DR4. I have to tell you that these genes are not approved yet to be guilty, while other studies have to be estimated on this topic.

Other important thing is that scientists are suspecting mutation in the gene responsible for the synthesis of insulin receptor (INSR), but this is still not approved.

You have to know that HLA DR3 and DR4 mutation are associated mainly to the autoimmune type of gestational diabetes. Because as you probably know, HLA stands for human leukocyte antigen and changes in this HLA system are leading to autoimmune process, like diabetes and others.

The mutation in the INSR gene can explain the insulin resistance, but you have to know that such mutation is observed in patients with diabetes type 2.

3. Third thing is that the baby is not suffering from insulin resistance, because there are no such changes in the baby’s body.

Generally, the development of the baby depends on the amount of glucose in the blood of the mother. So, when there is an elevated blood glucose concentration in the mother’s blood, the baby receives more of it. Because of this, women with gestational diabetes are giving birth of overweight babies.

Important fact is that in some cases mothers with gestational diabetes are not developing diabetes type 2 in future, but the rest of them are developing it.

Therefore, scientists are taking in consideration that this is a matter of genetic predisposition, but this is not approved yet.

Hope it helped!

Dr.Alba