Gestational Diabetes Mellitus (Gdm) In Pregnant Women: The Case Of Australian Women

Prevalence’s of GDM    1
Symptoms of GDM    2
Causes of GDM    3
Managing GDM    3
Impact of GDM on the Public Health Sector    3
Public Health Nutrition Initiatives for Addressing GDM in Pregnant Women    4
Carbohydrate Intake    5
Caloric Intake for Normal and Underweight Women    5
Caloric Intake for Overweight/Obese Women with GDM    5
Vitamin and Mineral Supplementation    5
Gestational Diabetes Mellitus (GDM) is defined as the degree of glucose intolerance that is first detected during pregnancy. This is the definition that applies whether insulin or only diet modifications are used for its management or treatment and whether or not the condition persists after pregnancy1. It is considered the most common metabolic complication of pregnancy2. GDM has been associated with both maternal and fetal morbidities therefore increasing the urgency of early diagnosis in order to reduce cases of maternal and fetal morbidities and allow for extra measures to be taken to allow, subsequent attempts as well as delaying and if possible preventing the onset of type 2 diabetes2. Although GDM is fairly common among pregnant women, its true rate of prevalence remains highly controversial and as a matter that generates heated debate. Approximated figures however show that approximately 7% of all pregnancies are complicated with GDM. These figures however range from 1 to 14% mostly depending on populations studied and diagnostic tests used. GDM appears as a result of a broad spectrum of genetic and physiological abnormalities that characterize diabetes outside pregnancy. Women suffering from GDM have been found to have a higher likelihood of developing diabetes even when they are not pregnant. Risks associated with GDM include and are not limited to; macrosomia, polyhydramnios, obesity and excessive weight gains3.

Prevalence’s of GDM

Recent studies show that GDM is on the rise. The Kaiser Permanente of Colorado screening program for example found out that case of GDM doubled from an initial 2.1% to 4.1% among a test sample of 36,403 pregnancies between the years 1994 to 20024. According to the first national report on incidence of gestational diabetes mellitus among Australian women of the year 2005-2005, GDM was diagnosed in 4.6% among pregnant women of between the ages of 15 and 49. This however represented an increase of 20% from the year 2000-01 to 2005-06. This is an alarming trend that needs to be checked and serious steps taken to avert further rises in cases of GDM. The research also found out that risk of being diagnosed with GDM increases with age; women between the ages of 15-19 years for example have a 1% chance of contracting GDM compared to 13% for women between the ages of 44-49. The study further found that women aged 30-34 accounted for more than a third of GDM cases in 2005-065.
In order to effectively diagnose GDM, 1the new standards of Medical Diabetes Association (ADA) recommended screening for undiagnosed type 2 diabetes at the first prenatal visit for women with a high diabetes risk factor. It further recommended that tests be performed at the 24 to the 28 week of gestation. Additionally, women who have been diagnosed with GDM should also be screened for persistent diabetes in the 6 – 12 week. Women with GDM are also encouraged to have life-long screening commitments6.  The Australian diabetes in Pregnancy Society (ADIPS) also drafted recommendations for the diagnostic of GDM in 1991. The guidelines they formulated have now been implemented nationally with only minor adjustments at the local level.

Symptoms of GDM

Worldwide, several diagnostic criteria are used in the diagnostic of GDM. The original criteria developed in 1964 and which is still widely used is based on the prediction of development of maternal diabetes16. The Australasian Diabetes in Pregnancy Society (ADIPS) developed consensus criteria used for diagnosis of GDM in 199117. These criteria while the basics remain the same have been restated over time and are now widely used.
Some of the symptoms associated with GDM include; maternal age over 35 years, poor previous obstetric clinical analysis, family history of type 2 diabetes, prediabetes or impaired fasting glycemia, obesity, polycystic syndrome and smoking during pregnancies. African-American, Native American also has a higher chance of contracting GDM. GDM is linked with strong possibilities of the mother developing types 2 diabetes in future and usually with severe perinatal outcomes with one of the possible outcomes being intrauterine programming.

Causes of GDM

While there are no well identified causes of GDM, research has shown it is highly likely caused by hormonal imbalance during pregnancy. As the placenta supplies the fetus with water and nutrients, it also produces hormones such as cortisol, estrogen and human placental lactogen which are necessary in maintaining the pregnancy. These hormones are thought to have a blocking effect on insulin; this effect is called the contra-insulin effect which usually occurs between the 20 and 24 week of the pregnancy7. These hormonal imbalances consequently lead to increased resistance to insulin by the pregnant woman leading to impaired glucose intolerance8.

Managing GDM

All women should receive nutritional counseling which would help them personalize their medical nutritional therapy (MTN) while at the same time strictly adhering to the guidelines of the American Diabetes Association. The MTN should incorporate adequate nutrients and calories to meet the needs of the pregnancy. In the case of obese women, a 30% calorie restriction should be imposed in order to reduce hyperglycemia and plasma triglycerides while at the same time leading to no increases in ketonuria1.
Women with GDM should also enroll in a program of moderate physical activities; this has been shown to significantly lower glucose concentration. Impacts of rigorous exercises however, still require more studies to show if they have any impacts on neonatal complications1.
Human insulin should also be used when insulin is prescribed. Self-monitoring of blood glucose (SMBG) should therefore act as a guide to the dosage and timing of the insulin. The use of insulin analogs has however not been adequately tested in the treatment of GDM1.

Impact of GDM on the Public Health Sector

The recent increasing trend of GDM is leading to growing concerns on its effects now and in future on the public health care system. GDM for example will lead to significant increases in pregnancy complications which will require increased resources to manage effectively in order to reduce potentially adverse prenatal outcomes9. Additionally, approximately 50% of women with GDM are expected to develop type 2 diabetes which will increase stress on our current health care structures even further10.
The total cost of managing GDM and diabetes on the economy is alarmingly high. In Australia for example, it is estimated that the annual cost of managing GDM and type 2 diabetes is $6 Billion with the annual health care cost per person being $4,025 as long as there are no associated complications. This figure however rises to approximately $16,698 in people with diabetes related complications such as micro and macro vascular complications15.
GDM has also been attributed to increasing cases of obesity. Studies have shown for example that infants of women with GDM are at increased risks of having diabetes, impaired glucose tolerance and developing obesity as young adults11, the increased risks are or maybe independent of genetics11. This is bound to put even more pressure on a society that is already grappling with serious proportions of obesity and which it has continually been unable to handle.
Diabetes is also known to lead to compounded health complications which includes;
GDM and diabetes related complications have been known to be a leading cause of death. Diabetes for example is listed as a contributor of 3% of deaths in Australia. This figure can however rise to about 9% if complications caused deaths are included. When diabetes related complications are listed as the underlying cause of death, it is associated with 67% causes of death, 30% kidney related failures, 20% heart failure, 25% cancer and 8% stroke15.
Poor psychological well-being has also been known to be caused by GDM leading to even more medical complications. Studies have estimated that about 10% of people suffering from GDM are usually referred for further psychological care. This is beside the fact that very little studies have been done on the psychological effects GDM has on its patients15.

Public Health Nutrition Initiatives for Addressing GDM in Pregnant Women

Recent focus on the treatment of GDM has been trying to gauge the effectiveness of treating GDM with conventional treatments which include exercises and proper diets versus using pharmacological intervention. Studies have concluded that women who strictly adhere to established dietary and exercise programs alone have higher positive outcomes with pharmacological interventions. Crother et al9, for example found out that the rate of serious prenatal complications such as death, bone fracture, shoulder dystocia and nerve palsy reduces from 4 to 1%. Recent nutritional initiatives focused on addressing GDM in pregnant women include:

Carbohydrate Intake

This initiative involves encouraging pregnant women especially those with Gestational diabetes mellitus to consume a minimum of 175 grams of carbohydrates per day based on the Dietary Reference Intake (DRI) for pregnant women in order to provide glucose to the fetal brain while also preventing ketosis. In this nutritional initiative however, total carbohydrate intake should never be allowed to go beyond 45% of energy consumed by the pregnant women in order to prevent hyperglycemia in women especially those with GDM13.

Caloric Intake for Normal and Underweight Women

This initiative usually involves a registered dietitian encouraging normal and underweight pregnant women alike to consume adequate calories in order to have an appropriate rate of weight gain. This should however be used with guidance from the Dietary Reference Intakes for pregnant women13.
Although the area of nutritional research on the prevention of GDM is far from exhausted, certain measures need to be taken in future to reduce cases of GDM. The nutritional initiatives could include caloric intake for overweight and obese women with GDM and vitamin and mineral supplementation. These two initiatives are explained in detail in the following two sections below.

Caloric Intake for Overweight/Obese Women with GDM

This nutritional intervention is majorly concerned with reducing rates of weight gain or obesity in pregnant women especially those with GDM. It therefore involves encouraging an optimum energy restriction in order to slow weight gain in women with gestational diabetes mellitus who are also overweight. Calorie intake of approximately 70% of the Dietary Reference Intakes is considered appropriate to slow down weight gain in women with GDM without necessarily compromising the fetal or causing ketonuria.

Vitamin and Mineral Supplementation

Vitamins are crucial compounds utilized in small quantities for various body metabolic functions.  Vitamin initiative therefore involves rectification of a situation where daily dietary intakes do not meet the Dietary Reference Intakes for pregnant women. Nutritionists in this case should encourage vitamin and other mineral supplements to prevent or counter any nutritional deficiencies that could be caused by the pregnancy14. Though it is generally held that common balanced diet foods have enough of the crucial body vitamins sometimes pregnant women may suffer a vitamin deficiency and therefore should be given vitamin supplements in addition to their daily balanced diet meals.

Poor social-economic and education status, ignorance on pregnancy and pregnancy related complications, lack of proper training of medical practitioners, taboos associated with pregnancy, lack of sensitivity about the condition, medical practitioners recklessness as well as dietary habits have all provided a favorable environment for increased cases of GDM and have been associated with increased prevalence of this condition.
Inter-pregnancy care research on the other hand needs to be stepped up in order to be able to achieve optimal outcome in pregnancies especially after GDM. Issues that will need to be addressed in future clinical trials would include; whether or not to breastfeed and if yes for how long, whether it would be beneficial to delay subsequent pregnancies and establish optimal choices of hormonal contraceptives. While the focusing of most studies is on how to prevent type 2 diabetes in women especially those suffering from GDM. Studies are also needed to; find effective ways of delivering preventive interventions through but not limited to increased health care funding and translational research, establishment of optimal timings and cost effective ways of preventing diabetes and create a link between prevention of diabetes in women with GDM with preventing metabolism syndrome and obesity in their children.

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