If you’ve been diagnosed with gestational diabetes, the standard testing schedule is four times a day: once when you wake up (fasting) and once after each of your three main meals. Your fasting reading should be below 95 mg/dL, and post-meal readings should stay below 140 mg/dL at one hour or below 120 mg/dL at two hours, depending on which timing your provider recommends.
The Four Daily Blood Sugar Checks
Most providers will ask you to check your blood sugar at these four points each day:
- Fasting: First thing in the morning, before eating or drinking anything. Target: below 95 mg/dL.
- After breakfast: One or two hours after your first bite (your provider will specify). Target: below 140 mg/dL at one hour, or below 120 mg/dL at two hours.
- After lunch: Same timing as breakfast.
- After dinner: Same timing as breakfast.
These targets come from the American Diabetes Association’s 2024 standards of care and are widely used by OB providers in the U.S. Your provider may set slightly different thresholds, but these numbers are the benchmark.
Why the Timing Matters
Post-meal testing is designed to catch your blood sugar near its peak. Research using continuous glucose sensors found that pregnant women typically hit their highest post-meal reading around 70 to 80 minutes after eating. By two hours, blood sugar has often dropped enough that you might miss a spike entirely. That’s why many providers prefer the one-hour mark: it’s closer to the actual peak and correlates better with outcomes like birth weight and delivery complications.
Start your timer from your first bite, not from when you finish the meal. If your provider says “one hour post-meal,” that means 60 minutes from the start of eating.
Can You Test Less Often?
A pilot study comparing twice-daily testing to four-times-daily testing found no meaningful difference in the proportion of readings that exceeded targets. The gap in fasting glucose between the two approaches was tiny. Still, four-times-daily testing remains the standard because it gives you and your provider a complete picture across all meals. Some providers do reduce the frequency once your numbers are consistently in range for several weeks, but that’s a conversation to have with your care team rather than a decision to make on your own.
What Happens Before Diagnosis
Gestational diabetes screening typically happens between 24 and 28 weeks of pregnancy. The most common approach in the U.S. is a two-step process. First, you drink a sugary solution and have your blood drawn one hour later. If that result is 140 mg/dL or higher (some providers use 130 mg/dL as the cutoff), you move on to a three-hour test where your blood is drawn fasting and then at one, two, and three hours after a larger glucose drink. Two or more elevated values on the three-hour test confirm the diagnosis. A one-hour result of 190 mg/dL or higher on the initial screen is enough for a diagnosis on its own.
Some people are screened earlier, at their very first prenatal visit. Early screening is recommended if you have risk factors like a BMI of 30 or higher, polycystic ovary syndrome, a previous gestational diabetes diagnosis, a prior baby weighing 9 pounds or more, or a family history of type 2 diabetes. This early test checks whether you may have had undiagnosed diabetes before pregnancy rather than the insulin resistance that develops later in gestation.
When Readings Trigger a Change in Treatment
Most women manage gestational diabetes with dietary changes and activity alone. But your provider will watch for a pattern of readings above target that signals diet alone isn’t enough. Common thresholds for adding medication: fasting values above 105 mg/dL on more than one occasion, post-meal readings above 120 mg/dL three or more times in a single week, or any post-meal reading above 150 mg/dL. The exact thresholds vary by practice, but the key point is that one high reading doesn’t automatically mean you need medication. Providers look for a pattern over days.
Logging your numbers along with what you ate makes these patterns much easier to spot. Many providers use apps or paper logs where you record the time, reading, and meal details. This is genuinely useful, not busywork: it helps you identify which foods or combinations cause spikes so you can adjust.
Continuous Glucose Monitors
Continuous glucose monitors, the small sensors worn on your arm that read glucose every few minutes, are increasingly used during pregnancy. The 2025 ADA standards now recommend that CGM data can be used alongside finger-stick testing to help meet blood sugar goals in pregnancy. For gestational diabetes specifically, CGM is not yet considered a replacement for finger-stick checks because there aren’t enough studies establishing specific CGM targets for this group. But if you’re having trouble identifying post-meal spikes or want a fuller picture of your overnight numbers, a CGM can be a helpful add-on. The decision is typically individualized based on your treatment, insurance coverage, and preferences.
Testing After Delivery
Blood sugar usually returns to normal soon after delivery, but gestational diabetes significantly raises your long-term risk of developing type 2 diabetes. Guidelines recommend a two-hour glucose tolerance test 6 to 12 weeks postpartum to confirm your levels have normalized. This test uses the same drink-and-wait format as your earlier screening. Insulin resistance can resolve much sooner than six weeks, but the postpartum window is chosen to coincide with your routine follow-up visit. If that test comes back normal, ongoing screening every one to three years is still recommended because the elevated risk persists for years.