Gestational Diabetes-What is it?

What is gestational Diabetes, what causes gestational diabetes, how can gestational diabetes be prevented, what are the symptoms of gestational diabetes, how is gestational diabetes treated. All these questions and more will be answered in the following article.

Gestational diabetes is diabetes occurring during pregnancy (gestation), happening to women not previously known to be suffering from diabetes and caused by pregnancy related factors. Occurring usually during the third trimester, the condition results from the improper functioning of insulin receptors occasioned by insulin blocking hormones and other agents such as lactogen produced by the placenta.

As a result the body becomes insulin resistant and the blood sugar level of the mother to be becomes abnormally high. If untreated the condition can affect the baby’s health. Thus such babies tending to be large may have difficulty passing through the birth canal. They are also at risk of jaundice and low blood sugar. Left untreated it can also result in seizures or still birth. In addition to that, such children have an increased risk for developing childhood obesity and Type 2 diabetes later on in life.

For those mothers who leave the condition untreated, they run the risk of developing type 2 diabetes after pregnancy. They will also tend to be prone to pre-eclampsia and Caesarean section.

Generally speaking gestational diabetes has few or no symptoms. Although some women may complain of fatigue, increased thirst, increased urination, bladder infection, nausea and vomiting, blurred vision and yeast infections, it is still best diagnosed by screening during pregnancy. Such tests will reflect abnormally high levels of glucose in the blood.

Two common criteria used to diagnose gestational diabetes both based on blood sugar levels are the 100 gram Glucose Tolerance Test according to Carpenter and Coustan; and the criteria for diagnosis of gestational diabetes according to Indian National Diabetes Data group. The 100 gram Glucose Tolerance Test posits

Fasting 95 mg/dl

1 hour 180 mg/dl

2 hours 155 mg/dl

3 hour 140 mg/dl

Due to the lower cut off values, this criteria leads to a diagnosis of gestational diabetes in 54 percent more pregnant women. The American Diabetes Association however agree with these same values for the purpose of determining gestational diabetes.    

Whereas the gestational diabetes according to the National diabetes Data Group posits

Fasting 105 mg/dl

1 hour 190 mg/dl

2 hours 165 mg/dl

3 hour 145 mg/dl

Screening options for detecting the presence of Gestational diabetes vary. First there is the Non-challenge Glucose test. So named because it measures the glucose levels in blood samples without challenging the subject with glucose solutions. This test can be either made on the subject when he has fasted, 2 hours after a meal or at any random time. Challenge tests on the other hand require that a glucose solution is drunk and glucose levels in the blood is then measured. Where diabetes is present, the test would reflect an above higher than normal level. In a non-challenge test, when on two separate test occasions, a blood sugar (glucose) level is found higher than 126 mg/dl (mmol) after fasting or over 200mg/dl (11.1 mmol/1) on any occasion, the diagnoses of gestational diabetes is made. These tests are cheap and inexpensive to administer, however they have lower test performance when compared to the other tests.

On the other hand the Screening Glucose challenge test known also as the O’Sullivan test, is a simplified variant of the oral glucose test (OGTT). Unlike the OGTT test however, it requires the subject to drink a solution containing 50 grams of glucose and measuring blood levels 1 hour later. In this test a cut-off point of 140 mg/dl (7.8 mmol/l) will enable 80% of women with gestational diabetes to be detected.

The Oral Glucose tolerance test can also be performed to determine gestational diabetes. Here though the solution given the subject is usually 75g or 100g and blood glucose level is measured at the start and on set intervals thereon.

Other tests that a woman may be required to take in order to determine whether she has gestational diabetes is the Urinary glucose test. This is because they may have high glucose levels in their urine a condition known as glycosuria.

Having said as much though, factors considered when deciding to screen or not screen for diabetes differs slightly depending on which side of the Atlantic you’re on. In the United Kingdom obstetricians rely on risk and a random glucose test for diagnosing gestational diabetes, whereas in the United States, universal screening with a glucose challenge test is preferred. On the other hand the American Diabetes Association and the Society of Obstetricians and Gynaecologists of Canada recommend routine screening unless the woman is low risk.

What are the risk factors for gestational diabetes? They follow

Age. Women older than 25 are more likely to develop gestational diabetes. Also women who have Polycystic Ovary syndrome – a set of symptoms due to hormonal imbalance and characterised by heavy periods, irregular or no menstrual periods, acne, patches of thick dark velvety skin, excess body and facial hair, pelvic pain. Another risk factor is a previous diagnosis of prediabetes, impaired fasting glycaemia or impaired glucose tolerance. Also having a first degree family relative-in other words a parent or sibling who has type 2 diabetes is also a risk factor. In addition to this is weight. Where your body mass index (BMI) is 30 or more, your risk for developing the condition increases. Race is also a factor. As in diabetes type 2, it is the case also that persons of the African American, American Indian, Hispanic, South East Asian and Pacific Islanders groups tend to be more prone to developing gestational diabetes. Furthermore, if you has a woman delivered a baby weighing more than 9 pounds (4.1 kilograms) - a situation known as macrosomia, you are at increased risk for the condition. Further to this, genetic predisposition borne out by at least 10 genes especially TCF7L2 and smoking have been fingered as potential risk factors for developing gestational diabetes.

Having said this, the general advice is that all pregnant women undergo screening since statistics show that 40% to 60% of women with gestational diabetes exhibit no apparent risk factor for it. The doctor will check blood sugar after delivery and again six to 12 weeks thereafter to make sure blood sugar level has returned to normal.

So then, how is the condition treated? A combination of blood sugar management through the aid of blood sugar monitoring, diet, exercise and where necessary insulin use is the way to go. As with diabetes generally, it is essential that the patient monitor and controls her blood sugar. As such she may be required to monitor her blood sugar four to five times a day. First thing in the morning and after meals.

Also note that consumption of a healthy diet in appropriate portions is another great way to control blood sugar. This will consist of vegetables, fruits and whole grains-nutrient rich high in fibre, low in calorie foods. Such a diet would also limit highly refined carbohydrate products like white bread, white rice and pasta. It is suggested that a registered dietician or your doctor should be consulted when planning the diet so that you can be adequately advised.

Exercising too, moderately done will help to lower the blood sugar level by increasing cell sensitivity to insulin and making your body move glucose into your cells.

Where the above measures prove insufficient however, then the aid of medication like insulin may be called for. 10 to 20 percent of women with gestational diabetes require such insulin treatment. In addition, though metformin is an option, some people may opt not to use it due to the condition of being pregnant.

Finally the close monitoring of the baby cannot be overstated. Monitoring of the baby’s progress via repeated ultrasound or other tests may be necessitated. Where labour does not come as at when due, then the doctor may induce it as delivery after the due date may increase the risk of complications for you and your baby.

Generally therefore, gestational diabetes though a serious condition that can affect a woman and a child’s health during and after pregnancy has a positive prognosis when adequately diagnosed and treated. In addition, its effective management as in most diabetes cases can lead to health benefits for the persons involved- the mother and the child and cuts down their risk for developing Type 2 diabetes in future.