The glucose test in pregnancy is performed practically in all pregnant women during the second trimester of pregnancy. But what is the test really about and why is it done routinely? We will find out about it in this post.
What is glucose?
To understand the importance of glucose testing in pregnancy. First, we should know that glucose is a form of sugar that humans get from foods such as fruit, pasta, or white bread.
Our body is capable of using it as a source of energy, but for this, glucose must pass from the intestine to the bloodstream and from there enter the cells of our body.
For this to happen, the blood vessels in the intestine absorb glucose and then the action of a hormone called insulin, which is released by the pancreas, is essential. so that glucose enters the cells.
But what happens if there is not enough insulin or if our body has resistance to this hormone? In that case, the glucose will not be able to enter the cells and will stay in the bloodstream.
This causes an increase in blood glucose levels which is known as hyperglycemia and, depending on how high it is and how long the levels remain high, it can indicate the presence of diabetes.
Why is glucose testing done during pregnancy?
Elevated blood glucose levels in pregnant women who have never had diabetes can indicate the presence of gestational diabetes. It is generally transient since it appears for the first time during pregnancy and usually disappears after giving birth.
The global prevalence of gestational diabetes ranges between 7% and 14%, gestational diabetes affects between 3-9% of pregnancies. The causes are not entirely clear, but it appears that in pregnancy hormones can hinder the action of insulin in the body, creating some resistance to insulin.
In most cases, pregnant women compensate for this resistance by producing a greater amount of insulin, reaching an adequate level to regulate blood glucose levels.
However, if they do not produce enough insulin, gestational diabetes can develop. In addition, there are some risk factors that increase the chances of developing this type of diabetes, such as:
- Be over 35 years old.
- Present obesity.
- Previous pregnancy with gestational diabetes.
- Having first-degree relatives with diabetes mellitus or a family history of insulin resistance.
- Present polycystic ovary syndrome.
Risks of gestational diabetes
If not properly controlled, gestational diabetes can pose risks to both mother and baby:
Risks for the mother:
- The risk of suffering from preeclampsia is increased, a pathology that produces an increase in blood pressure among other complications.
- It increases the risk of developing gestational diabetes in future pregnancies and type 2 gestational diabetes throughout life.
- The chances of cesarean delivery are increased.
Risks for the baby:
- If the cases of macrosomia are frequent, that is, the baby is larger than normal, which increases the risk of complications during delivery, among others.
- The risk of premature birth is increased, both naturally and programmed, in cases such as macrosomia.
- It increases the risk of the baby suffering from hypoglycemia after birth, so it is necessary to observe the sugar levels of the newborn for a few hours after birth. In addition, certain studies indicate that children are also at risk of developing obesity and type 2 diabetes.
As you can see, gestational diabetes involves risks not only for the mother but also for the fetus. To avoid these complications it is essential to detect them as soon as possible, something that is achieved through the glucose test in pregnancy.
When is glucose testing done during pregnancy?
In general, the glucose test in pregnancy is performed in practically all pregnant women between 24 and 28 weeks of gestation. However, it has been found that there are some risk factors that increase the risk of developing gestational diabetes and in these cases.
The test can be advanced to the first trimester of gestation, with the aim of detecting possible gestational diabetes as soon as possible. In addition, even if the test was performed in the second trimester if throughout the pregnancy.
The pregnant woman has signs related to gestational diabetes such as macrosomia or increased amniotic fluid (polyhydramnios), the glucose test could be repeated.
How is glucose testing done during pregnancy?
Generally, the pregnancy glucose test is done in two phases:
O’Sullivan’s test: consists of ingesting, without having to go to the test on an empty stomach, an oral solution that contains about 50 grams of glucose. One hour after ingestion, a blood test is performed on the pregnant woman to determine the amount of glucose in the blood. The results obtained are interpreted as follows:
- If the values are lower than 140 mg/dl, the presence of gestational diabetes is ruled out.
- If the result is ≥140 mg/dl, it will be necessary to perform a second test called the Oral Glucose Tolerance Test or Oral Glucose Overload Test to confirm the presence of gestational diabetes.
Oral glucose overload: this test must be performed on an empty stomach and also requires a preparatory diet the three days prior to the test, with a carbohydrate intake greater than 150 grams.
If the pregnant woman’s diet is low in carbohydrates the days before the test, it is possible that a false-positive result will occur since her pancreas will not be used to generating insulin. The diet is necessary to prepare the pancreas and that the result is as plausible as possible.
The oral glucose load test is performed as follows:
- A first blood test is performed on the pregnant woman, to determine her basal blood sugar value.
- The woman ingests a liquid solution that contains 100 grams of glucose.
- Blood samples are taken every hour for the next 3 hours.
The results obtained are interpreted as follows:
- Baseline sample ≥105 mg/dl.
- Sample after one hour of ingestion: ≥190 mg/dl.
- Sample after two hours of ingestion: ≥165 mg/dl
- Sample after three hours of ingestion: ≥145 mg/dl.
If two of the values obtained are equal to or greater than those mentioned above, gestational diabetes is diagnosed. However, if only one value appears increased, oral glucose intolerance is diagnosed and it is recommended to repeat the test after 3-4 weeks.
During the performance of any of these tests, the pregnant woman must remain in the medical center, at rest, without eating, drinking, or smoking.
What happens if I am diagnosed with gestational diabetes?
If the glucose test in pregnancy confirms gestational diabetes, a series of dietary and exercise guidelines will be indicated, and in some cases, the prescription of medications will be necessary.
On the one hand, a healthy diet, rich in fiber and low in fat, will be prescribed, as well as practicing moderate exercise for about 30 minutes a day. In general, if there are no contraindications, exercising during pregnancy is always beneficial.
In general, these measures are able to keep blood glucose levels stable, however, on some occasions, it may be necessary to take a drug to control these levels. In these cases, it will always be the specialist who indicates the treatment to follow.
Normally, gestational diabetes disappears after delivery, however, the WHO advises checking that glucose levels have returned to normal between 6 and 12 weeks after giving birth.
We hope it will help you understand what the glucose test is and its importance during pregnancy. As you have seen, it is essential to detect possible gestational diabetes in time and thus be able to control it and avoid complications for both the mother and the baby.
In addition to the glucose test, many other tests are performed in pregnancy to monitor both the health of the pregnant woman and that of the fetus. Do you know the non-invasive prenatal test? This test allows knowing the risk of the fetus to present chromosomal alterations, with only a maternal blood test from the 10th week of pregnancy.
