Glucose tolerance test during pregnancy. Glucose tolerance test during pregnancy: at what stage and how to take it? What does a glucose tolerance test show during pregnancy?

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Scientific editor: M. Merkusheva, PSPbSMU named after. acad. Pavlova, medical practice.
February, 2019.

Synonyms: glucose tolerance test, GTT, glucose tolerance test, sugar curve, Glucose tolerance test (GTT), Oral GTT in pregnancy

According to statistics, up to 14% of pregnant women are prone to gestational diabetes mellitus (impaired glucose tolerance). This is a serious medical problem that can lead not only to severe complications during pregnancy, but also to provoke the development of type II diabetes mellitus (DM) in a woman in the future.

The glucose tolerance test (GTT) makes it possible to timely detect pathological sugar levels in the expectant mother and prevent complicated pregnancy and the development of diabetes.

General information

Diabetes mellitus in pregnant women (gestational) has differences in comparison with the classic course of the disease. First of all, this concerns the quantitative indicators of the test - what predetermines a violation of carbohydrate metabolism for non-pregnant patients can be considered the norm for expectant mothers. That is why, to study pregnant women, a special glucose tolerance test is performed according to the O’Sullivan method. The analysis involves the use of a so-called “sugar load”, which makes it possible to identify the pathology of glucose absorption in the body.

On a note: expectant mothers are at risk for developing diabetes. This is due to the restructuring of metabolic processes in the body, as a result of which disturbances in the absorption of one or another component are possible. In addition, gestational diabetes may long time be asymptomatic, so diagnosing it without GTT is difficult.

Gestational diabetes itself is not dangerous and goes away on its own after the baby is born. However, if you do not provide supportive therapy that is safe for mother and baby, the risk of complications increases. Also among the dangerous consequences for women is the development of type II diabetes mellitus.

Gestational diabetes is associated with an increased risk of obesity, glucose intolerance, and type 2 diabetes in the offspring.

Timing of GTT in pregnant women

A glucose tolerance test should be performed at 16-18 weeks of pregnancy, but no later than 24 weeks. Earlier research will be uninformative, since insulin resistance (resistance) in expectant mothers begins to increase only in the second trimester. The test can be carried out from the 12th week if the patient has elevated sugar in a biochemical analysis of urine or blood.

The second stage of the examination is prescribed at 24-26 weeks, but no later than the 32nd, since at the end of the third trimester the sugar load can be dangerous for both mother and child.

If the results of the analysis coincide with the criteria for newly diagnosed diabetes, then the expectant mother is referred to an endocrinologist to prescribe effective therapy.

Indications

GTT is prescribed to all pregnant women to screen for gestational diabetes between 24 and 28 weeks of pregnancy.

A glucose tolerance test is prescribed for pregnant women up to 24 weeks who are at risk for:

The test is not advisable in the following cases:

early toxicosis with pronounced symptoms;
liver diseases;
pancreatitis (inflammation of the pancreas) in acute form;
peptic ulcers (damage to the inner lining of the digestive tract);
stomach ulcer, gastritis;
Crohn's disease (granulomatous lesions of the digestive tract);
dumping syndrome (acceleration of the movement of stomach contents into the intestines);
the presence of inflammatory, viral, infectious or bacterial diseases;
late pregnancy;
if necessary, strict bed rest;
with a fasting glucose level of 7 mmol/l and above;
while taking medications that increase glycemic levels (glucocorticoids, thyroid hormones, thiazides, beta blockers).

Decoding

Note: If at the first stage of the test the fasting blood glucose level exceeds 7 mmol/l, then additional diagnostics are carried out (determination of glycosylated hemoglobin, C-peptide) and a diagnosis of “diabetes mellitus of a certain type” (gestational, type 1, 2) is made. After this, an oral exercise test is prohibited.

There are a number of nuances to deciphering the test:

only venous blood is indicative (it is not recommended to use arterial or capillary blood);
established reference values do not change with the duration of pregnancy;
after exercise, one value is sufficient to diagnose gestational diabetes;
if ambiguous results are obtained, the test is repeated after 2 weeks to exclude a false result;
the analysis is repeated after childbirth to confirm or refute gestational diabetes.

Factors that may affect the result:

deficiency of microelements (magnesium, potassium) in the body;
disturbances in the functioning of the endocrine system;
systemic diseases;
stress and anxiety;
simple physical exercise(moving around the ward during the test);
taking sugar-containing medications: cough medicines, vitamins, beta blockers, glucocorticosteroids, iron supplements, etc.

The appointment and interpretation of the analysis is carried out by a gynecologist, endocrinologist.

Preparing for GTT

To conduct a glucose tolerance test, venous blood is required, so the preparation rules for venipuncture are standard:

blood is donated strictly on an empty stomach (break between meals is at least 10 hours);
on the day of the test you can only drink plain water without gas, other drinks are prohibited;
It is advisable to perform venipuncture in the morning (from 8.00 to 11.00);
on the eve of the analysis, it is necessary to abandon drug and vitamin therapy, since certain drugs can distort the test result;
the day before the procedure, it is advisable not to overwork either physically or emotionally;
It is prohibited to drink alcohol and smoke before the test.

Additional dietary requirements:

3 days before venipuncture, it is forbidden to follow diets, fasting days, water fasting or fasting, or change your diet;
Also, 3 days before the test you must consume at least 150 grams. carbohydrates per day, while the last meal on the eve of venipuncture should contain at least 40-50 grams. carbohydrates.

Carrying out a test in pregnant women

The O’Sullivan method involves conducting a glucose tolerance test with a load in 3 stages.

Stage No. 1

30 minutes before the test, the patient must take a sitting/lying position and completely relax;

The health worker takes blood from the ulnar vein using venipuncture, after which the biomaterial is immediately sent to the laboratory.

The results of this step allow the doctor to diagnose probable gestational diabetes if the blood glucose level is above the normal value of 5.1 mmol/L. And “definite gestational diabetes” if the result is more than 7.0 mmol/l. If the test is not indicative or the results obtained are ambiguous, then proceed to the second stage of the test.

Stage No. 2

The body is given a special “load” in the form of a sugar solution (75 g of dry glucose per glass of warm water). Within 5 minutes, the patient should drink the liquid completely and remain in a sitting (lying) position for an hour. The sweetness of the drink can cause nausea, so you can dilute it a little with squeezed lemon juice. After 1 hour, a control blood sample is taken.

Stage No. 3

2 hours after taking the solution, another blood sample is taken. At this stage, the doctor confirms or denies the diagnosis of gestational diabetes.

From the very beginning of pregnancy, significant changes in metabolic processes, including carbohydrates, occur in a woman’s body. In order to identify violations of the latter, determination of blood sugar levels and an oral glucose tolerance test during pregnancy are used. Compared to men, diabetes mellitus is much more common among women, and there is a clear association with the gestational period and childbirth - GDM (gestational diabetes mellitus).

Methods for identifying impaired carbohydrate metabolism

The prevalence of diabetes among pregnant women on average in Russia is 4.5% of their total number. In 2012, the “Russian National Consensus” defined GDM and recommended for practical application new criteria for its diagnosis, as well as treatment and postpartum observation.

Diabetes mellitus in pregnant women is a disease characterized by high blood sugar levels, which is detected for the first time, but does not meet the criteria adopted for a newly diagnosed (manifest) disease. These criteria are:

fasting sugar content is more than 7.0 mmol/l ( further in the text the same names of units of measurement) or equal to this value;
glycemia, confirmed in a repeated analysis, which at any time during the day and regardless of diet is equal to or greater than 11.1.

In particular, if a woman’s fasting venous plasma sugar level is less than 5.1, and during an oral glucose tolerance test 1 hour after exercise it is less than 10.0, after 2 hours it is less than 8.5, but more than 7.5 - these are normal options for a pregnant woman. At the same time, for non-pregnant women, these results indicate a violation of carbohydrate metabolism.

At what stage is a glucose tolerance test performed during pregnancy?

Identification of carbohydrate metabolism disorders is carried out in stages:

Stage I of the examination is mandatory. It is prescribed at the first visit to a doctor of any profile by a woman for up to 24 weeks.
At stage II, an oral glucose tolerance test is carried out with 75 grams of glucose at 24-28 weeks of pregnancy (optimally 24-26 weeks). In certain cases (see below), such a study is possible up to 32 weeks; if there is a high risk - from 16 weeks; if sugar is detected in urine tests - from 12 weeks.

Stage I consists of conducting a laboratory test of glucose in blood plasma on an empty stomach after an 8-hour (no less) fast. It is also possible to test blood regardless of diet. If the norms are exceeded, but the blood glucose level is less than 11.1, then this is an indication for repeating the test on an empty stomach.

If the test results meet the criteria for newly diagnosed (manifest) diabetes, the woman is immediately referred to an endocrinologist for further observation and appropriate treatment. If the fasting glucose level is higher than 5.1 but less than 7.0 mmol/l, GDM is diagnosed.

How to perform a glucose tolerance test during pregnancy

Indications

A glucose tolerance test is performed on all women in the following cases:

There are no deviations from the norm in the results of phase I examination in the early stages of pregnancy.
The presence of at least one of the signs of a high risk of GDM, ultrasound signs of carbohydrate metabolism disorders in the fetus, or certain ultrasound signs of fetal size. In this case, the test can be carried out up to and including the 32nd week.

Signs of high risk include:

high degree of obesity: body mass index is 30 kg/m2 and above;
presence of diabetes mellitus in immediate (first generation) relatives;
history of gestational diabetes mellitus or any carbohydrate metabolic disorders; in this case, testing is carried out at the first visit to the doctors (from 16 weeks).

Is a glucose tolerance test dangerous during pregnancy?

This study does not pose any risk to the woman or fetus up to 32 weeks. Carrying it out after the specified period can be dangerous for the fetus.

Testing is not carried out in the following cases:

early toxicosis of pregnancy;
compliance with bed rest;
presence of diseases of the operated stomach;
the presence of chronic cholecystopancreatitis in the acute stage;
the presence of an acute infectious or acute inflammatory disease.

Preparation

The conditions for conducting a glucose tolerance test include:

Normal meals for the previous 3 (at least) days with a daily carbohydrate content of at least 150 g in the diet.
Mandatory carbohydrate content of 30-50 g in the last meal.
Fasting (but not restricting water intake) for 8-14 hours the night before testing.
Elimination (if possible) of admission medicines containing sugar (pharmaceutical preparations of vitamins and iron, antitussives, etc.), as well as beta-blocking, beta-adrenomimetic and glucocorticosteroid drugs; They should be taken after blood sampling or inform the doctor about the need to take them before testing (for adequate interpretation of test results).
Doctor's warning about conducting a test while taking progesterone.
Stop smoking and keep the patient in a sitting position until the end of testing.

Stages of implementation

They consist of:

Taking the first blood sample from a vein and analyzing it. If the results indicate the presence of newly diagnosed or gestational diabetes mellitus, the study is stopped.
Carrying out a sugar load with normal results of the first stage. It consists of the patient taking 75 g of glucose powder dissolved in 0.25 liters of warm (37-40 ° C) water for 5 minutes.
Subsequent collection and analysis of further samples after 60 minutes, and then after 120 minutes. If the result of the second analysis indicates the presence of GDM, then the 3rd blood draw is canceled.

Interpretation of glucose tolerance test results during pregnancy

So, if the fasting blood glucose concentration is less than 5.1, this is normal, above 7.0 is manifest diabetes; if it exceeds 5.1, but at the same time is below 7.0, or 60 minutes after a glucose load - 10.0, or after 120 minutes - 8.5 - this is GDM.

Tab. 1 Threshold values of venous plasma glucose for the diagnosis of GDM

Tab. 2 Threshold values of venous plasma glucose for the diagnosis of overt diabetes during pregnancy

The correct approach to identifying and treating diabetes (if necessary) significantly reduces the risks of complications during pregnancy and childbirth itself and the degree of threat of developing diabetes in the distant future in women predisposed to it.

Paying attention to your health will help the expectant mother safely carry and give birth to a healthy baby.

40 weeks of pregnancy is not only a time of waiting, hope, excitement and joy. During this period, the expectant mother also undergoes numerous examinations, and also takes all kinds of tests. The purpose of such careful monitoring is to monitor the course of pregnancy, as well as timely diagnosis of problems and correction of pathological conditions. Among the studies whose validity is controversial is the glucose tolerance test. How advisable is it to take this test for all expectant mothers without exception?

Glucose and its role in the body of a pregnant woman

The key source of energy for the lion's share of the body's cells is sugar. It is “brought” into the body by foods rich in carbohydrates, and some sugar (in the form of glycogen) is also secreted by the liver. Useful component enters the blood, which carries it throughout the body. However, glucose cannot penetrate the cells on its own; insulin comes to its aid.

Normal, insufficient or excessive production of this protein substance determines the glucose content in the blood - within the normal range or with a deviation in the direction of increase or decrease. Increased, as well as insufficient, inclusion of glucose in the blood has bad influence both on the health, and, consequently, the well-being of the woman, and on the course of pregnancy.

High glucose levels during pregnancy are fraught with the development of fetal pathologies, a sharp increase in the child’s weight, and metabolic disorders in a woman (including the development of gestational diabetes, late toxicosis).
Insufficient presence of sugar in the blood often leads to disorders general condition expectant mother — headache, feeling of weakness, fatigue, increased sweating, blurred vision.

One of the tests to diagnose the level of sugar inclusion in the blood of a pregnant woman is a glucose test with an additional load.

Glucose tolerance test during pregnancy - justified need or unnecessary examination

Prescribing this type of examination to an expectant mother causes a negative reaction in many women, and this is quite understandable. The procedure often causes discomfort in the form of nausea and dizziness. In addition, the glucose load test is carried out in the morning, for several hours (about 3). At this time (and also the day before in preparation for the study), you should exclude the consumption of any kind of food, which also often poses a certain difficulty for a “pregnant” body. It is for these reasons that many pregnant women refuse to conduct research.
How justified is the purpose of this type of analysis?

Glucose tolerance during pregnancy. Who is at high risk?

Among the risk factors that require additional examination in the form of a test to identify glucose tolerance are:

Excessive obesity in a pregnant woman (mass index exceeds 30).
During a blood sugar test, which was carried out when the pregnant woman was registered, the inclusion of glucose in the blood was recorded at a level above 5.1 mmol/l.
There is a history of a disorder in the form of gestational diabetes (during previous pregnancies).
Urine analysis showed the presence of glucose in the urine during pregnancy.
The pregnant woman has relatives (close) with established diabetes mellitus.
The expectant mother is carrying large fruit or there has been a birth of a large baby in the past.
The pregnant woman’s age has “crossed” the threshold of 35 years.

The presence of at least one of the factors listed above is in favor of conducting a tolerance test. Moreover, the presence of “aggravating circumstances” is often an indication for prescribing a glucose tolerance test twice - when a woman applies for registration (classic analysis to determine sugar content) and in the second trimester of pregnancy.

When is it indicated to donate blood for glucose during pregnancy?

The detection of the symptoms listed below should force the expectant mother to undergo an unscheduled examination with a carbohydrate load.

The appearance of a metallic taste in the mouth.
The need to urinate frequently.
Increased fatigue, constant fatigue.
Elevated blood pressure readings.

The final decision on whether to conduct a glucose test is made, of course, by the woman, but she should listen to the recommendations of the doctor who is monitoring her pregnancy. Some conditions of a pregnant woman require additional attention, so you should not neglect the doctor’s advice. Gestational diabetes, which is not detected in a timely manner, threatens serious complications not only for the woman, but also for the child she is carrying. A proper diet combined with individual recommendations will negate Negative influence pathology.

Glucose test during pregnancy: preparation for the test

Proper preparation for analysis is one of the most important components reliable result research.

A few days (three days is enough) before the test, the expectant mother should completely eliminate all fatty and spicy foods, coffee, cakes, and smoked foods from her diet. By the way, a woman “in position” should not abuse such delicacies the rest of the time. It is best to stick to a neutral diet.
Taking medications can also affect the test results, resulting in a false result. This statement applies especially strictly to: multivitamins, medications containing iron, drugs to lower blood pressure, diuretics, corticosteroid hormones. When taking any medicines The pregnant woman is obliged to notify the doctor about the therapy.
It is very important to maintain the usual mode of physical activity, not to “sleep”, but also not to be too zealous.
The last meal on the eve of the test should occur at least 8 hours before (and preferably 10-14 hours before). During this period you can only drink water.
It is also strictly prohibited to smoke and drink alcohol (which is already contraindicated for pregnant women).
You should brush your teeth at night. Before taking the test, it is better to skip this hygienic procedure, because Some components of toothpaste can distort test results.
Try to avoid increased anxiety and stressful situations.

How to take a glucose test during pregnancy

The optimal period for taking a stress test for sugar is considered to be the period from the 24th to the 28th week of gestation. The Carbohydrate Load Test procedure includes the following steps:

A pregnant woman comes to a medical facility and donates the first portion of venous blood on an empty stomach. Depending on the data obtained at the first stage, a decision is made on further research. So, if the glucose level is already exceeded, the exercise test is not performed. The woman is referred for further examination and clarification of the diagnosis with suspected gestational diabetes. If the sugar level is normal, a glucose tolerance test is prescribed.
The second stage is glucose loading during pregnancy by oral administration of a glucose solution. A woman should drink warm water in an amount of 250-300 ml, in which 100 g or 75 g of dry glucose is diluted. The amount of monosaccharide is determined by the doctor ordering the study. 60 minutes after absorption of the glucose solution, the blood sugar concentration is measured. An alternative method of administering the solution may be intravenous administration of the composition, although direct injection of glucose into the blood is not often practiced.
The third stage involves recording blood glucose numbers 2 hours after the carbohydrate load test.

The data obtained is checked against the standards and a conclusion is drawn about the state of health of the pregnant woman.

Glucose levels during pregnancy: interpretation of test results

Interpretation of test results is based on data obtained as a result of three-time measurement of the level of glucose inclusion in the blood. When assessing the result obtained, you can rely on the following criteria:

1. Indicators of blood sugar concentration when collecting biological material on an empty stomach and without load are:

below 5.1 - 5.5 mmol/l (taking into account laboratory reference values) is normal;
in the range of 5.6 - 6.0 mmol/l - deviations in glucose tolerance;
6.1 mmol/l or more - suspicion of diabetes (in a number of laboratories this indicator is in the range of 7 mmol/l and above).

2. Measuring glucose incorporation 60 minutes after an additional carbohydrate load:

less than 10 mmol/l is normal;
in the range of 10.1 - 11.1 mmol/l - deviations in glucose tolerance;
11.1 mmol/l or more – suspected diabetes.

3. Fixing the sugar content 120 minutes after a glucose load:

less than 8.5 mmol/l indicates normal;
in the range of 8.6 - 11.1 mmol/l - deviations in glucose tolerance;
11.1 mmol/l and above is a clear deviation, possibly gestational diabetes.

Table for assessing glucose levels during pregnancy: norm and deviations

Depending on the type of research method, the normal limits in different laboratories may vary slightly. In view of this, it is very important to evaluate the result solely in accordance with the criteria of a given research center.

Analysis result: increased glucose during pregnancy

Even if the test results reveal a discrepancy with the normal criteria, you should not immediately panic. This violation may be due to:

Increased hormonal activity of the adrenal glands.
Excessive activity of the thyroid gland.
Pathologies of the pancreas.
Long-term use of glucocorticoids.

Additional examinations will help clarify the cause of the violations.

Test result: low glucose during pregnancy

A downward deviation is less common than an elevated glucose level. This violation may be associated with:

Severe form of early toxicosis.
Unbalanced diet of the expectant mother.
Lack of body weight in a pregnant woman.

A low sugar content, in addition to disturbing the general condition, can also lead to increased production of ketone bodies, which have a toxic effect on the female body. Drug therapy for low sugar levels is not prescribed. A woman is advised to have a balanced diet with sufficient calories. In some cases, glucose drips may be prescribed.

Glucose test during pregnancy: contraindications for testing

A referral for a glucose load is issued by a doctor who is observing the expectant mother. A number of conditions are a contraindication to this type of research. These include:

Gestation period is more than 28 weeks. Conducting a tolerance test in the third trimester of expecting a baby can be dangerous for him. That is why the study can be scheduled in the period from the 28th to the 32nd week of gestation of a toddler strictly for medical reasons. After the 32nd week, a glucose load is never prescribed.
Glucose intolerance.
Presence of infection (including mild colds), foci of inflammation.
Bed rest for a pregnant woman. To adequately assess the test results, moderate physical activity of the expectant mother is necessary.
Exacerbation of pancreatitis - inflammation of the pancreas.
Ulcerative lesions of the gastrointestinal tract.
Therapy with drugs aimed at increasing glycemic levels. Conducting research in this case will be pointless.
If the blood sugar level (when taken on an empty stomach) exceeds 7.0 mmol/l. The exact norm depends on the criteria of a particular laboratory (it could be 5.1 mmol/l).
Severe toxicosis. The analysis procedure is unpleasant and can further aggravate the manifestations of toxicosis.

Additional sugar loading by performing a glucose test during pregnancy is a mandatory test. However, the decision to conduct research in each individual case should be taken by the doctor and the woman together.

The doctor prescribed you to undergo a glucose tolerance test, but you are afraid or do not know how this examination is carried out? In this article you will learn everything about GTT, its contraindications, we will dispel your doubts and tell you how to prepare for it.

A glucose tolerance test is an examination that helps determine a woman’s tendency to diabetes or detect its latent form.

In other words, this examination is called a “sugar load”. Thanks to this test, you can diagnose the disease in time and take action. necessary measures to avoid undesirable consequences.

Why take a glucose tolerance test during pregnancy?

Statistics show that about 15% of pregnant women suffer from gestational diabetes, otherwise known as gestational diabetes.
This disease, like many others, occurs against the background of weakening female body and increased load on it during pregnancy
During pregnancy, a woman's body must produce more insulin, which is responsible for normal blood sugar levels.
But the body does not always cope with this task, and then the amount of sugar increases and diabetes develops.

Is a glucose tolerance test required during pregnancy?

It is imperative to undergo a GTT examination if a woman falls into one of the following categories:

was diagnosed with this disease in previous pregnancies
if a pregnant woman has problems gaining weight - a body mass index above 30
if the weight of previous children at birth was more than 4.5 kg
if one of your blood relatives has this disease
Sugar is present in urine test

If a woman is at risk, then a GTT examination should be carried out, as a rule, at 16-18 weeks and a second time at 24-28 weeks. If necessary, the test is performed again, but no later than 32 weeks.

Is it dangerous to perform a glucose tolerance test during pregnancy?

Until 32 weeks, the glucose tolerance test is not dangerous for either the mother or the baby. Imagine eating a donut with sweet jam for breakfast
Could it make you feel bad or could it somehow harm your health? Of course not! And the amount of glucose a woman needs to take is approximately equal to this breakfast
But an unreasonable refusal of GTT can be harmful if elevated blood sugar is not detected in time and the necessary measures are not taken to normalize glucose levels

How and where to take a glucose tolerance test during pregnancy?

10-14 hours before the test, a pregnant woman should not eat, only drink clean water, in the morning the examination is carried out on an empty stomach.

Do not take any medications, not even vitamins, because... this may affect the results of the examination.

This examination is carried out in antenatal clinics and various private centers.

How is a glucose tolerance test performed during pregnancy?

In the morning, a woman donates blood to determine her sugar level.
If blood sugar is elevated at this stage of the examination, then the test is not performed further and a repeat examination is scheduled on another day.
If the level is normal, the expectant mother is given a solution with 75-100 grams of glucose per glass of water at room temperature.
After 1 hour and 2 hours, blood is drawn for analysis; if necessary, blood is drawn after 3 hours
After 2 hours, the glucose level should normalize, but if it is elevated, then a repeat examination will be scheduled

It is important, for correct test results, to drink the glucose solution immediately, no longer than 5 minutes before. During the test, the pregnant woman should not leave the laboratory and completely avoid physical activity.

The glucose solution is sickly sweet, so a pregnant woman may feel sick. To prevent this from happening, the test is not performed if the woman is suffering from toxicosis.

When should you take a glucose tolerance test during pregnancy?

The optimal time to undergo this examination is the period from 24 to 26 weeks of pregnancy
In general, the test is carried out from the 24th to the 28th week, but no later than 32 weeks, because This test carries a serious burden on the pregnant woman’s body and on later may be hazardous to the health of the woman and fetus
If a woman is at risk, the test is carried out at more early- at 16-18 weeks

Contraindications for glucose tolerance test during pregnancy

There are reasons why a woman should refuse to undergo a GTT examination, these include the following:

if a woman suffers from serious liver disease, such as pancreatitis
in the presence of dumping syndrome
if a pregnant woman is diagnosed with Crohn's disease
the expectant mother has peptic ulcers
if on the day of the test the woman has symptoms of an “acute abdomen”
Infectious diseases are present in the expectant mother's body
presence of inflammatory processes
The woman has been placed on strict bed rest
period more than 32 weeks

Norm, results and interpretation of the glucose tolerance test during pregnancy

The blood glucose level of a pregnant woman is slightly higher than that of other people, which is necessary for the normal development of the fetus, but there are indicators that it should not exceed.

So, the diagnosis of “diabetes mellitus in pregnancy” is made based on the following examination results:

during the first blood draw in the morning on an empty stomach - 5.1 mmol/l
when taking blood an hour after taking a glucose solution - 10 mmol/l
when drawing blood after 2 hours - 8.6 mmol/l
when drawing blood after 3 hours - 7.8 mmol/l

If during the first examination the blood glucose level was higher than the given values, then a repeat examination is carried out on another day.
If suspicions are confirmed, the pregnant woman is diagnosed with gestational diabetes.
If there are suspicions, but the test is normal, then the pregnant woman is prescribed to take it again after about 2 weeks to exclude erroneous results
When diagnosing diabetes, the test is repeated after childbirth, or rather after 6 weeks, to identify its cause, i.e. Is it associated solely with pregnancy or perhaps the woman has developed real diabetes mellitus
Treatment of gestational diabetes consists of adjusting the diet of the expectant mother; moderate physical activity will also be beneficial
A pregnant woman will have to visit the doctor more often and undergo additional ultrasound examinations to monitor the baby's weight gain. Childbirth with this diagnosis is usually scheduled for 37-38 weeks of pregnancy

How and why to take a glucose tolerance test during pregnancy: tips and reviews

Let's summarize:

The glucose tolerance test is a very necessary examination that reveals hidden forms of diabetes mellitus in pregnant women or a tendency to it
The test is usually carried out at 24-28 weeks, it can be earlier or later if there is cause for concern, but no later than 32 weeks
Blood sampling is carried out exclusively in the morning and on an empty stomach, the pregnant woman takes a glucose solution and then the analysis is repeated after an hour, two and three
If blood glucose levels are elevated, the examination is repeated, and once the results are confirmed, a diagnosis is made
GTT is not dangerous for a child or a pregnant woman, except in cases where the examination is contraindicated

A glucose tolerance test during pregnancy is a test that allows you to monitor important indicator the state of the woman’s body - the level of glucose in the blood. Basically, the sugar test is carried out in relation to the detection of diabetes.

The analysis should not be confused with a hemotest, which identifies individual food intolerances.

Women who have relatives suffering from diabetes are at risk. In this case, for a pregnant woman, undergoing GTT is a mandatory precaution.

It is enough to undergo it once, when there is no obvious suspicion of diabetes and the result is negative. However, it is possible to take the test again during pregnancy if there is a suspicion of increased blood glucose.

Why do they do it?

Often, expectant mothers ask doctors why they are prescribed a glucose tolerance test if they are not at risk. If elevated blood sugar levels are detected, a number of measures are prescribed that are acceptable during pregnancy.

Prescribed to everyone as a preventive measure

Carrying a child is a time of great changes in a woman. But these changes are not always for the better. The body experiences major changes while carrying a baby.

Considering the heavy loads that the body as a whole undergoes, some pathologies appear exclusively while expecting a child. Diabetes mellitus is one of these diseases.

In these situations, pregnancy serves as a provoking factor for the latent course of the disease. Therefore, as preventative measure GTT analysis during pregnancy is necessary and important.

How to take it

The first logical question that women ask during pregnancy is at what period of time GTT is performed. A glucose tolerance test is done in the first trimester along with a number of other tests.

In order to properly undergo the examination, you must carefully prepare:

exclude nervous disorders;
limit physical activity;
do not make significant changes in the diet - eat as usual (do not follow any diets);
do not eat food (within 8 hours before the test).

The test is not performed if there are any diseases in the acute stage, even in the case of a common runny nose. Any changes of this kind will greatly affect the results of the study, so these options must be excluded.

GTT is done on an empty stomach (you can drink water, but not during testing). It is carried out by drawing blood from a vein 3 times, with an interval of 1 hour between the second and third sampling:

First, blood is drawn.
After this, a special sweet liquid (glucose syrup of a certain concentration) is drunk.
For the next hour, the patient should not eat, drink, or exercise - all this can greatly distort the test results.
The next blood draws are carried out an hour and two after the first analysis.
After this time after taking the cocktail, the blood sugar level in healthy person comes back to normal. This is what the test results should reflect.

Must consult a doctor

If the readings are high and not within normal limits, an immediate consultation with a doctor monitoring the pregnancy is prescribed. If the first test shows an elevated sugar level, a repeat appointment will most likely be scheduled to rule out a possible error.

There are a number of reasons why a false result is possible:

the eight-hour diet was not followed before donating blood;
significant changes in diet during the three days before the test (increased or insufficient carbohydrate intake);
carbohydrate metabolism disorders;
excessive physical activity;
stressful condition;
infectious diseases (including respiratory acute respiratory viral infections, acute respiratory infections);
reception of any medical supplies affecting carbohydrate metabolism (warn your doctor about the use of medications).

GTT norms

Numerical indicators of 7 mmol/l and below are within normal limits. If elevated levels are observed, a diagnosis of gestational diabetes is usually made. This type of disease occurs in 14% of women.

The figure 7 mmol/l is very arbitrary. GTT norms for pregnant women are presented in the table below:

The observed dynamics are normally maintained, but the numbers may be different depending on various factors.

It is worth noting that the upper limit - the maximum permissible indicator - is also very arbitrary. And in different sources the numbers vary. Therefore, no independent interpretations; only a qualified doctor observing your pregnancy will be able to interpret the results correctly and indicate the presence possible illness or its absence.

Glucose thresholds

Gestational pathology is called because before pregnancy the woman did not show any signs of diabetes. After childbirth, when the body is restored, the glucose level either returns to normal, or diabetes develops into another type - T1DM (type 1 diabetes), or it turns out that the pregnant woman has T2DM (type 2 diabetes).

If a woman has problems with carbohydrate metabolism earlier before pregnancy or already during pregnancy, it is better to take a glucose tolerance test at 25 weeks to identify possible deviations from the norm.

Depending on the method of introducing the glucose load into the body, two types of analysis are distinguished: oral (or oral) and intravenous. The second method is more often used if the patient for some reason cannot take the “sweet cocktail” orally.

The OGTT analysis is carried out with a load - consuming 75 g of glucose dissolved in a glass of water. To be sure, there should be no significant changes in the pregnant woman’s diet for three days before donating blood. In some cases, women donate blood from a vein without ingesting a glucose cocktail.

Repeated checks may be ordered

The study is not just for adults. For children over 14 years old also apply this method. The difference lies in the amount of load taken and in the numerical indicators included in the normal range.

For children under 14 years of age, analysis without load is acceptable. The norms differ only up to the age of five; later they correspond to adult values from 3.3 to 5.5 mmol/l. Up to a year, the level fluctuates around 2.8 – 4.4 mmol/l.

It is worth noting that the presence of elevated blood glucose does not necessarily indicate diabetes mellitus in the patient, it may be a sign of disorders such as:

overactive thyroid gland;
increased hormonal activity of the adrenal glands;
taking glucocorticoids for a long time;
pathology of the pancreas.

Low glucose levels - hypoglycemia - occur in a number of isolated cases. Low sugar is usually associated with an overdose of insulin medications in diabetes.

How dangerous

The analysis itself is not dangerous. This applies to the no-load test.

In relation to exercise testing, it is possible to “overdose” blood sugar levels. This happens only when the pregnant woman already has high level glucose content, but there will be symptoms that clearly indicate a violation of carbohydrate metabolism.

OGTT is not carried out just like that. During pregnancy with stress, the test is performed a maximum of 2 times and only in case of serious suspicion of diabetes. While blood is donated once a trimester without fail, so the blood sugar level can be found out without additional stress.

Eat different fruits

Like any medical procedure, GTT has a number of contraindications, including:

congenital or acquired glucose intolerance;
exacerbation of chronic stomach diseases (gastritis, disorders, etc.);
viral infections (or pathologies of another nature);
severe toxicosis.

In the absence of individual contraindications, the test is safe even during pregnancy. In addition, judging by the reviews, it does not present any particular discomfort when performed.

The women describe the glucose cocktail as “simply sweet water", which is not difficult to drink. Of course, if the pregnant woman does not suffer from toxicosis. The need to draw blood 3 times within two hours leaves a slight discomfort.

However, in most modern clinics (Invitro, Helix), blood is taken from a vein completely painlessly and does not leave any unpleasant impressions, unlike most municipal medical institutions. Therefore, if there are any doubts or concerns, it is better to take the test for a fee, but with the proper level of comfort.

Don't worry - everything will be fine

In addition, you can always administer glucose intravenously, but to do this you need to inject it again. But you won't have to drink anything. Glucose is introduced gradually over 4-5 minutes.

Testing is contraindicated for children under 14 years of age. For them, it is carried out exclusively by drawing blood without being burdened by a glucose load.

Mirror belly
pregnant fruit analysis
passed

The volume of the sweet cocktail taken is also different. If the child weighs less than 42 kg, the dose of glucose is reduced.

Thus, performing the test with proper preparation and following the instructions does not pose a threat. And undiagnosed diabetes poses a danger to the fetus and mother.

Proper metabolism, including carbohydrate metabolism, is important for the development of the fetus and for the mother’s body during pregnancy. The detected pathology is subject to correction, which will certainly be prescribed by the observing obstetrician-gynecologist.

The presence of gestational diabetes complicates pregnancy and future births. That's why it's so important to register it with initial stage and make changes to help normalize blood sugar levels and minimize harm from the disease.

Therefore, when prescribing this test, expectant mothers should not worry, but pay due attention to the test. After all, prevention is best treatment, especially when we're talking about not about one life, but about two at the same time.

: Borovikova Olga

gynecologist, ultrasound doctor, geneticist

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