A common concern during the glucose screening test for gestational diabetes is consuming the highly concentrated, sugary drink. This test screens for gestational diabetes, a condition where the body does not properly regulate blood sugar during pregnancy. If you vomit the glucose solution after drinking it, the test is immediately invalid. This occurs because the body has not absorbed the full, standardized glucose load required for an accurate metabolic measurement.
Understanding the Glucose Screening Test
The glucose screening test, often called the one-hour glucose challenge test, is routinely performed between the 24th and 28th weeks of pregnancy. This test is the first step in the diagnostic process for gestational diabetes. The procedure involves quickly drinking a liquid containing 50 grams of glucose, typically within five minutes.
Exactly one hour after consumption, a blood sample is drawn to measure the body’s glucose level. This precise timing captures the peak concentration of glucose, reflecting how efficiently the body processes the sugar load. Fasting is generally not required for this initial screening.
Immediate Actions After Vomiting
If you vomit the glucose drink, notify the medical staff immediately. The test is nullified because it is impossible to determine how much of the required 50 grams of glucose was absorbed before the episode. Do not attempt to continue the test or wait until the next day to report the incident.
Once the test is canceled, focus on your well-being and personal safety. Vomiting can be dehydrating, so drink small, frequent sips of water to restore fluids. Contacting your healthcare provider right away ensures they can document the failed attempt and plan for a prompt retest, minimizing any delay in screening.
Options for Retesting and Alternative Methods
After a vomiting incident, your healthcare provider will determine the next course of action, usually involving rescheduling the test. The most common protocol is to repeat the one-hour, non-fasting 50-gram glucose challenge test on a different day. This allows for a fresh attempt at the standard screening procedure.
Alternatively, the provider may recommend bypassing the screening test and moving directly to the more comprehensive diagnostic test. This is the three-hour Oral Glucose Tolerance Test (OGTT), which requires fasting for at least eight hours. The OGTT involves a higher concentration of glucose (typically 100 grams) and requires four blood draws: a baseline fasting draw, followed by draws at one, two, and three hours after the drink.
If you are unable to tolerate the glucose solution again, or have a history of severe nausea, alternative diagnostic approaches exist.
Alternative Diagnostic Approaches
One option involves closely monitoring blood sugar levels at home using a glucose meter. This requires finger-prick testing multiple times a day for a set period, providing a profile of your glucose response to normal meals. Some providers may also accept alternative forms of glucose, like a specific number of jelly beans or certain natural glucose solutions. The accuracy of these methods can vary and must be approved by your clinic.
Tips for a Successful Second Attempt
To increase the chances of completing a second test successfully, several strategies can help mitigate nausea caused by the sugary drink. Since the high concentration (osmolarity) of the solution often causes stomach upset, chilling the beverage beforehand can make it more palatable. Many clinics keep the drink refrigerated for this reason.
When consuming the solution, aim to drink it quickly but steadily, completing the entire bottle within the required five-minute window. Minimizing the time the drink spends in your mouth reduces the sensation of sweetness that triggers nausea.
During the one-hour waiting period, remain seated and avoid strenuous activity. Exertion can alter the test results and potentially worsen feelings of sickness. Focusing on a distraction, such as reading a book or watching a movie, can help pass the time and take your mind off any mild discomfort.
After the blood draw is complete, have a protein-rich snack or meal available immediately. This stabilizes your blood sugar and prevents a sugar crash that can lead to shakiness or headache.