Diabetes is a metabolic disease that affects how the body utilises and controls blood sugar levels. Normally, after a diet of carbohydrate, the converted glucose which is absorbed into the blood stream is transported to the cells and tissues of the body where it is further converted at cellular level into ATP molecules to provide energy for the cells to function. In diabetic conditions, the transportation of glucose from the blood to the body cells is impaired, which accounts for a perpetual high blood glucose levels when tested.
The impaired transportation of glucose might be as a result of inability of the pancreas to secrete the hormone insulin which is responsible for the shuttling of blood glucose to the cells. In other cases, the problem is not from the pancreas but rather as a result of insulin resistance at cellular levels which renders ineffective the work of insulin on the blood glucose. Irrespective of the mechanism, diabetes remains very common in every population globally and an issue which many health organisation regard as serious due to the detrimental effect it has on the lives of infected individuals.
When diabetes or high sugar levels are observed during pregnancy, it is termed as gestational diabetes. Gestational diabetes is common in pregnancies especially in the last trimester and affects how the pregnant woman’s cells use up sugar or glucose. Blood glucose levels remains persistently high in the affected woman and affects the pregnancy and the baby’s health. It is expected for blood glucose levels to return to normal after delivery, although in some cases, the levels can remain high even after delivery which results in type 2 diabetes for the woman. It is also possible for a woman who has diabetes before becoming pregnant to maintain even higher glucose levels during pregnancy. This is often referred to as pregestational diabetes.
Gestational diabetes is more technically defined as Fasting blood glucose levels (FBG) > 5.3mmol/L and post prandial levels > 7.8mmol/L during pregnancy.
What causes gestational diabetes?
The exacted cause for gestational diabetes is not clearly understood but explanations have linked it’s development to the inhibition of the action of insulin by the presence of other hormones produced by the placenta including progesterone, cortisol, human placental lactogen, prolactin and estradiol.
The risk factors associated with gestational diabetes include
- Age > 25 years.
- Pre-existing type 1 or type 2 diabetes mellitus.
- Family history of diabetes mellitus.
- Women who are overweight.
- Women of African descent or black race.
- History of polycystic ovarian syndrome.
What are the signs and symptoms of gestational diabetes?
Gestational diabetes is usually asymptomatic and most women would not know they have gestational diabetes until screening is done. Polyuria, polydypsia and polyphagia are normal experiences in a normal pregnancy.
The signs that are suggestive of gestational diabetes are fast growing fetus where the fundal height is more than the gestational age, and also the presence of polyhydramnios.
How gestational diabetes is diagnosed
The signs and symptoms are not reliable in diagnosing gestational diabetes, blood glucose screening is the standard for diagnosing the condition. Various blood glucose screening test are used to record glucose levels.
- Routine blood glucose screening : FBG > 7.0mmol/L and RBG > 11.0mmol/L are suggestive of gestational diabetes. It is confirmed through more sophisticated glucose screening test.
- Initial glucose challenge test : This involves taking a bolus of glucose and one hour later, the blood glucose levels are checked. Glucose levels > 7.8mmol/L is diagnostic of gestational diabetes. This test can be more elaborately done as follow up.
- Follow up glucose tolerance test : also called oral glucose tolerance test (OGTT) is the gold standard. Here, the patient is asked to fast overnight and in the morning, the fasting blood glucose is checked. A bolus of glucose is given and one hour later, the glucose level is checked. The glucose level is checked at the 2nd hour and 3rd hour. FBS > 5.3mmol/L, 1st hour > 10.0mmol/L, 2nd hour > 8.6mmol/L and 3rd hour > 7.8mmol/L confirms gestational diabetes.
- Urinalysis : for presence of glucose in urine.
- Ultrasound scan to check for fetal abnormalities.
- Glycated haemoglobin test every 2 or 3 months.
Management of gestational diabetes
- Daily monitoring of blood glucose levels is very crucial. This can be done at home with a glucometer.
- Dietary advice where high sugar containing foods are restricted with oily foods.
- Mild exercise is encouraged in the management of gestational diabetes unless when contraindicated by another condition in the pregnancy.
- The use of hypoglycemic medications to control glucose levels when diet and exercise fails to work is indicated. Insulin injections and oral antidiabetics can be administered but with care.
- Close monitoring of the fetus is necessary and delivery is initiated if necessary.
Prevention of gestational diabetes
- Eating healthy foods rich in fibre and low in fat and calorie.
- Active exercise before and during pregnancy can help protect against gestational diabetes.
- It is important to try and lose excess weight before getting pregnant. Overweight women can plan a healthy weight loss plan as they plan to get pregnant.
Mayoclinic.org : “Gestational diabetes”
Wikipedia : “Gestational diabetes”