“I am pregnant and the gynaecologist has asked to do a blood glucose test. Why?”. This was a woman who wanted to find out why she should do the test. I have come across a lot of pregnant patients asking the same question. Let’s discuss.
The body breaks down the starch in our food into glucose which enters our bloodstream through special blood vessels. The pancreas produces a hormone known as insulin, which is responsible for helping the blood glucose enter our body cells for usage. Diabetes however occurs when there is absence of insulin or ineffective insulin, thus the glucose remains in the bloodstream. An individual may experience symptoms including excessive thirst, excessive hunger, frequent urination, fatigue and blurred vision.
During pregnancy, the placenta produces other hormones including progesterone and oestrogen which impair the action of the hormone insulin thereby raising the blood glucose after a meal. The placenta continues to produce more hormones which counter the action of insulin as the baby grows. This is known as Gestational Diabetes. Gestational Diabetes usually resolves after the baby is born, with regular monitoring of the mother’s blood glucose level.
“I am too young to have Diabetes”…..any woman can actually develop gestational diabetes but women older than 25 years easily develop gestational diabetes. Also, a family history of gestational diabetes can put a pregnant woman at risk of developing gestational diabetes. Women with excess weight are also at risk of developing gestational diabetes.
A lot of women who have gestational diabetes usually deliver healthy babies. In the event of a poorly managed case, the baby may grow very large (Macrosomia). Excess glucose in the mother’s bloodstream crosses the placenta which causes the baby’s pancreas to produce extra insulin leading to excessive birth weight and accompanying hypoglycaemia (low blood glucose). The baby may not be able to pass through the birth canal and may need a C-SECTION birth. In other cases, the baby may be born before its due date with accompanying respiratory problems. Gestational diabetes may increase the mother’s risk of developing hypertension (high blood pressure) and preeclampsia (a pregnancy complication characterized by high blood pressure) which both threaten the lives of mother and baby.
The gynaecologist will order a series of lab tests to help in screening for gestational diabetes. Most often a fasting blood glucose test is done first, the patient is made to fast overnight then the glucose level is then tested. The value is usually elevated in diabetics but normal in healthy patients. A two-hour post prandial test could be done as well. The patient fasts overnight then the glucose level is tested. The patient then goes to take a meal and exactly two hours later the glucose level is tested again. In normal patients, the blood glucose level would have returned to normal as compared to its elevation in diabetics. In addition, a glucose tolerance test is done. Here, the patient fasts overnight for at least 8 hours but not more than 16 hours. The fasting blood glucose level is tested and the patient is given a controlled dose of glucose, usually in a solution. The patient’s blood glucose level is checked every 30 minutes for two hours.
Constant monitoring of one’s glucose level can go a long way to help prevent gestational diabetes. Also, exercising regularly, as well as eating healthy is very important. Your doctor may require you to take insulin shots if your body is unable to clear glucose from your bloodstream. An important part of your treatment regimen is close monitoring of your baby to ensure that it lives healthy without any complications. Let’s spread this information. Knowledge is power.
Written by Emmanuel Arkoful, a professional Medical Laboratory Scientist.