OGTT test: How to detect gestational diabetes in pregnant women?

OGTT test: How to detect gestational diabetes in pregnant women?

Gestational diabetes can develop during pregnancy in some pregnant women who have never had problems with diabetes before. To detect this increase in the level of sugar in the blood, tests exist, including that of the OGTT test. What does it consist on ? And how is it going? The point with Emmanuelle Cohen, gynecologist-obstetrician at the Institut Mutualiste Montsouris.

Every month, at each consultation, the search for sugar is carried out via a urine dipstick in pregnant women. If an abnormal sugar level is detected, a blood glucose test or an OGTT test will be carried out afterwards.

Gestational diabetes: what is it?

Gestational diabetes is a dysregulation of sugar tolerance, leading to a more or less significant increase in glycemia (blood sugar level). It is the production of insulin that allows the body to regulate the amount of glucose in the blood. However, when the body develops resistance to insulin or produces little, there is an imbalance.

Gestational diabetes is first diagnosed during pregnancy. According to the 2021 national perinatal survey, gestational diabetes concerns 16.4% of future mothers.

What are the risk factors for gestational diabetes in pregnant women?

Due to their age, weight and medical history, some patients have a higher risk of developing gestational diabetes. Among the profiles concerned, we find:

. Pregnant women who are over 35 years old.

. Patients who are overweight or obese, with a body mass index greater than 25 before the onset of pregnancy.

. Moms who have a family history of 1st degree diabetes.

. Women who have had gestational diabetes in a previous pregnancy.

Emmanuelle Cohen, gynecologist-obstetrician, also notes that a suspicion on ultrasound, that the fetus is above the recommended growth curves (macrosomy), also represents a risk for the mother of developing gestational diabetes.

In first intention, it is then an OGTT test which is carried out in the 2nd trimester of pregnancy to detect diabetes.

What is the OGTT test and how is it done?

OGTT stands for “oral induced hyperglycemia”. This test detects the blood sugar level of the pregnant woman to check if the values ​​are normal.

To perform the OGTT test, the pregnant woman must go to a medical analysis laboratory. ” Patients are warned that the test can be a little long, as the aim is to take three successive blood samples to obtain a diagnosis “, explains the gynecologist-obstetrician. It takes about 2 to 3 hours. The screening takes place as follows:

  • A first blood test on an empty stomach since 12 hours. Failure to comply with this deadline distorts the result.
  • A 2nd blood test, one hour after ingestion of a glucose-based solution.
  • A 3rd blood test, two hours after the ingestion of glucose.

How to interpret the results?

The OGTT test result is negative if none of the three blood glucose values ​​meet or exceed the following thresholds:

  • fasting blood sugar: 0.92 g/L
  • glycaemia at 1 h: 1.80 g/L
  • blood sugar at 2 a.m.: 1.53 g/L

Positive OGTT test, what to do?

If the diagnosis is positive, lifestyle and dietary measures should be taken until the due date to limit sugar intake and regulate diabetes. ” Most of the time, an appointment is scheduled with a dietician, and sometimes a diabetologist ” emphasizes the gynecologist-obstetrician. Doctors recommend:

  • To adopt a special diet, called hypoglycidic, which consists in limiting fast sugars and slow sugars.
  • To do as much physical activity as possible, compatible with pregnancy: walking, swimming, prenatal yoga, etc.

« At the same time, the patient is asked to monitor her blood sugar levels by obtaining a specific device, which allows her to perform capillary blood sugar levels says Dr. Cohen. If, despite this device and the application of lifestyle and dietary measures, the diabetes is still not balanced, the medical profession may need to set up insulin treatment. The latter can sometimes lead to a risk of complications for the mother and the baby, leading the medical team to induce labor earlier.

Does the OGTT test cause side effects?

Because you swallow a fairly large amount of sugar, the OGTT test may not be tolerated. ” It may in some patients cause nausea and vomiting “says the doctor Emmanuelle Cohen. The test is then not possible. If this happens, two options are possible:

  • The mother-to-be can ask to take the test again.
  • The medical team carries out another type of blood test which is also a form of screening (even if it is not the one recommended as first intention).

What alternative to the OGTT test to detect gestational diabetes?

When the OGTT test is not feasible, the medical profession carries out another form of laboratory screening, which takes place in two stages:

  • fasting blood sugar
  • postprandial blood sugar, two hours after the meal, associated with glycated hemoglobin.

This process provides an overview of blood sugar levels over the past three months. The values ​​obtained then constitute a 2nd type of screening. The gynecologist-obstetrician Emmanuelle Cohen wishes, however, to reassure pregnant women: “ Gestational diabetes should not be a source of stress for expectant mothers. If it is well balanced and framed by lifestyle and dietary measures, it does not impact the health of the child. ».

Moreover, gestational diabetes is transient and normally disappears after childbirth.