What To Eat Before The Pregnancy Glucose Test?

If you are pregnant, it is essential to start prenatal care to ensure healthy outcomes. Doctors would also check blood glucose in pregnant women, and thus the question of what to eat before the pregnancy glucose test.

Doctors would generally carry out multiple health tests to ensure healthy outcomes. The American College of Obstetrician and Gynecologists recommend a range of tests to be done during pregnancy. You can learn more about these tests here [1].

Doctors often start with general tests like blood and urine tests and then move on to more specific tests. For example, doctors would also test all pregnant women for sexually transmitted diseases and some chronic health disorders. Additionally, doctors would also screen for the risk of congenital disabilities.

Why glucose test in pregnancy?

Perhaps the first question that comes to anyone’s mind is why to check blood glucose during pregnancy. After all, pregnancy is not a disease.

It is just a special physiological condition. However, there are many reasons for testing for blood glucose during pregnancy.

Firstly, it is vital to understand that diabetes is quite common in the US and globally. In urban regions, 10-12% of people are living with diabetes. These are massive numbers. But, what is worrisome is that one-third of them are not aware of their condition.

In a large number of cases, diabetes does not produce many signs and symptoms. Thus blood glucose test is the only way to diagnose the condition. In addition, in the majority of cases, the diagnosis of diabetes comes as a surprise during routine tests.

There are two kinds of diabetes that may affect pregnant women, type 2 diabetes and gestational diabetes.

Many women have pre-existing diabetes due to lifestyle issues, but they are unaware of it. Type 2 diabetes is a lifestyle disorder characterized by insulin resistance and high blood glucose levels.

Doctors would check for this kind of diabetes as early as possible, as it may hamper fetal growth. Additionally, the kind of prenatal care depends on the women’s health status. Timely diabetes care will also help avoid birth-related complications.

However, perhaps the more significant concern for doctors is gestational diabetes. It is diabetes that occurs during pregnancy.

In about 8-10% of all pregnant women, blood glucose levels become abnormally high during pregnancy. This rise in blood glucose occurs in the second trimester. Thus, doctors test for gestational diabetes between 24-28 weeks of pregnancy [2].

Blood glucose test in pregnancy has many benefits

If a woman had a high blood glucose level before 24 weeks of pregnancy, it is type 2 diabetes. Gestational diabetes is diabetes that occurs due to pregnancy in an otherwise healthy woman. Timely diagnosis of gestational diabetes not only helps provide proper prenatal care but also helps identify women at risk of developing diabetes later in life.

In most cases, gestational diabetes is a kind of temporary and pregnancy-associated problem. It means that most women diagnosed with gestational diabetes would become normal after childbirth. However, about one-fifth of women would ultimately develop type 2 diabetes.

If women are diagnosed with gestational diabetes, doctors generally treat it with lifestyle interventions like dietary changes, and medications are reserved for severe cases only. However, it will also alert the doctors; thus, they will take extra care of such women.

What to eat before the pregnancy glucose test?

A pregnancy glucose test does not differ from a regular diabetes test much. Thus, giving such a test after about 8 hours of fasting is essential. Hence, the best time to give such a test is in the morning, as a person is naturally not eating during the night.

One should avoid eating anything in the morning as it will result in false blood tests. Since, after eating, there is an upsurge in blood glucose levels. In pregnancy, a fasting blood glucose test is the preferred way of diagnosing diabetes.

Of course, one should not fast, especially for the blood test, as that may not be good for fetal health. This is another reason why one should give this test in the early morning.

However, there must be at least eight hours interval between the blood test and the last meal. However, this interval should not be more than 12 hours, as prolonged fasting would also result in faulty test values.

Another important question is what to eat in the evening before the pregnancy glucose test. Well, it is vital not to have a very hefty meal, instead just a usual meal. Before the pregnancy test, avoid foods high in carbs and sugar. Instead, eat foods rich in proteins and moderately high in fats.

Simply said, may eat regular healthy foods. There are not many dietary restrictions. Avoiding high-sugar foods is not important just for pregnancy tests. It is good to avoid sugary foods for good health. Nonetheless, avoid such foods the evening before the test, as they might cause unusually high blood sugar levels.

Further, remember that doctors may use other tests for gestational diabetes, too, like oral glucose tolerance tests. In such tests, they will give you a sugary drink to see how good your body is at processing sugars. Although not many precautions are needed in such cases, a person should still avoid a hefty meal before such tests.


Doctors would always test for diabetes during pregnancy. This is because they are interested in knowing if a person has type 2 diabetes or not. Additionally, they would also carry out tests between 24 to 28 weeks of pregnancy to exclude gestational diabetes.

What one can eat before the test and what one cannot depends on the kind of test. Generally, not many precautions are needed. In the cases of fasting blood glucose test, no food is consumed for eight hours before the test, and one should avoid hefty meals rich in sugars or meals very high in carbs.


  1. Routine Tests During Pregnancy. Accessed November 22, 2022. https://www.acog.org/en/womens-health/faqs/routine-tests-during-pregnancy
  2. Zhou T, Du S, Sun D, et al. Prevalence and Trends in Gestational Diabetes Mellitus Among Women in the United States, 2006–2017: A Population-Based Study. Frontiers in Endocrinology. 2022;13. Accessed November 22, 2022. https://www.frontiersin.org/articles/10.3389/fendo.2022.868094
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