GESTATIONAL DIABETES

In this post I am drifting from gynecological topics to a common obstetrical problem known as Gestational Diabetes Mellitus, (GDM). I am sure that you are all familiar with the diabetic epidemic going around the world. Twenty years ago there were 20 Million diabetics in the world and now there are 240 million and if we do nothing there will be 340 million diabetics within the next 20 years. Diabetes is a long term multiorgan disease,can you imagine so many sick people wandering around the world.
What is the cause of diabetes being so popular? It is our lifestyle factors like sugary drinks and bad take away food, no activity or exercise.

Recently a Doctor David Baker from University of South Hampton ,UK has postulated a theory that the imprints of chronic diseases such as heart disease, diabetes and stroke are laid in utero they are born with this imprint. These babies are usually small in weight and premature. They generally become fat by two years of age with the wrong type of nutrition.

This theory appears to me, that During World Wars 1 and 2 young women were neglected nutritionally and so now the baby boomers are suffering with these chronic diseases. Modern society has to pay more attention to nutrition and activity, to prevent the spread of these chronic diseases.

Now going back to diabetes there are several types of diabetes such Type1, Type2, Gestational Diabetes Mellitus and they happen for different reasons. A pregnant mother can have any of these.

Diabetes Mellitus usually means that our body is unable to maintain a healthy blood glucose level.
A hormone in the body called insulin helps to make a balance in our blood sugar. The blood sugar goes high if there is not enough insulin for the body's health or the body doesn't utilize this insulin properly.
The insulin is produced by cells called Beta Cells which are located in the pancreas. In Type 1 diabetes it usually happens in childhood the beta cells are destroyed so they do not have insulin. These individuals require artificial insulin to maintain there blood glucose throughout their life.
They need careful management and can live a normal life and women can have a safe pregnancy if looked after properly.
The other diabetes is called Type 2 which starts later on in life, but these days young adults are starting to get these problems due to obesity and lifestyle. The beta cells still secrete insulin but usually it may not be enough or the body becomes resistant to insulin, however young women suffering from Type 2 diabetes can be looked after during pregnancy by strict medical management before, after and during the pregnancy.
Some women who are quite normal before getting pregnant develop diabetes during pregnancy, this is addressed as Gestational Diabetes. During pregnancy hormonal changes can make you less responsive to insulin. The increasing levels of placental lactogens and oestregens interfere with insulin function.
This increases until 28 weeks of pregnancy and generally the need for insulin is at its highest.
Recent studies show that diagnosis or management of GDM is beneficial for the mother and the baby and the next generation.
There is still some controversy about this screening program, many countries including Australia do screening for all pregnant women during pregnancy, there is some conflict if this should only be done in high risk women and secondly at what stage that this should be done.

I feel that it is worthwhile doing a fasting glucose of all women at the initial visit with their other blood tests, and if it is more than 5.5 then they can have the full test for diabetes called oral glucose tolerance test.(OGTT)
Some people like to do a full OGTT in high risks groups and these are:
1- Age over 40 plus
2- Obesity BMI more than 35
3- Family history of diabetes mellitus or GDM
4- Women from some countries ie: India, China, South Asia and Pacific Islanders (In Nauru 1/3 of the population is diabetic)
5- Poor obstetric history eg: previous still birth, repeated miscarriages, previous GDM
6- Previous birth of a baby weighing 4.5 Kilograms or more
7- Other genetic factors
8- Polycystic Ovarian Syndrome
9- Any medications like Cortisone
10-Anyone who has given birth to more than 5 children

Although there is no international agreement as yet on screening for GDM universally, however in Australia this is done on every pregnant patient at 24-28 weeks. The patients at high risk are often investigated early.
Initially we did a glucose challenge test which involved one hour blood glucose level after seventy five grams of glucose solution and if one hour glucose was more than 10 a full OGTT was done.
This glucose challenge test is no longer carried out or required.

OGTT is done after the patient has been fasting for 10 hours, a fasting glucose is done and then the patient is given 75 grams of glucose and two further blood samples are taken at 1 hour and 2 hours.
There is some controversy about these blood levels as well;
1-The fasting should be more or same as 5.1mml/litre (Some labs take this figure up to 5.8)
2-One hour 10mml/litre (Some labs do not take this sample)
3-Two Hours 8.5mml/litre ( Some labs take it less than 7.9)

You have to take into consideration the area you live in, the ethnic groups and the laboratories practice.

The risk and management of GDM will be discussed in the next post.