If you’ve been diagnosed with gestational diabetes, your target blood sugar levels are: below 95 mg/dL fasting, below 140 mg/dL one hour after meals, or below 120 mg/dL two hours after meals. These are the goals recommended by both the American Diabetes Association and the American College of Obstetricians and Gynecologists, and they haven’t changed in recent guidelines.
Your Daily Blood Sugar Targets
Here are the specific numbers you’re aiming for each time you check:
- Fasting (first thing in the morning): below 95 mg/dL
- One hour after a meal: below 140 mg/dL
- Two hours after a meal: below 120 mg/dL
Your provider will tell you whether to check at the one-hour or two-hour mark after eating. Most practices pick one or the other, not both. The one-hour check catches the peak of your blood sugar spike, while the two-hour check confirms your body is bringing levels back down efficiently. Either timing works for keeping tabs on how well you’re managing.
If you’re on insulin, your care team may also set a lower bound for these numbers. The ADA’s most recent guidance suggests a fasting range of 70 to 95 mg/dL and a one-hour postmeal range of 110 to 140 mg/dL for women on insulin, because going too low carries its own risks. If you’re managing with diet and exercise alone, you’re simply aiming to stay under the upper limits.
How Often to Test
Most providers will ask you to check your blood sugar at least four times a day: once fasting in the morning and once after each of your three main meals. Some may also ask for a check before meals or before bed, depending on how your numbers are trending. This can feel like a lot, but the frequent checks are what give you and your provider a clear picture of which foods and meals are causing spikes.
Start your timer from your first bite of food, not from when you finish eating. That’s a common source of confusion, and it can make your readings look artificially high or low depending on which direction you get it wrong.
What These Numbers Are Designed to Prevent
The primary reason for keeping blood sugar in this range is to reduce the chance of your baby growing too large, a condition called macrosomia. This is generally defined as a birth weight over 9 pounds (about 4,000 grams). When your blood sugar runs consistently high, your baby receives more glucose than needed and stores the excess as fat, which leads to a larger baby. That increases the risk of birth injuries, emergency cesarean delivery, and shoulder complications during vaginal birth.
Macrosomia isn’t exclusively caused by gestational diabetes. Babies born to mothers without diabetes can also be large. But controlling maternal blood sugar and staying within recommended weight gain during pregnancy are the two most effective ways to lower the risk.
How You Got These Numbers: The Screening Process
Most women in the U.S. are screened between 24 and 28 weeks of pregnancy using a two-step process. The first step is a glucose challenge test where you drink a sugary solution containing 50 grams of glucose. Your blood is drawn one hour later. If your level comes back at 140 mg/dL or higher, you move on to the diagnostic test.
The diagnostic test is a longer, three-hour version. You fast overnight, then drink a 100-gram glucose solution. Your blood is drawn at fasting, one hour, two hours, and three hours. The cutoffs are:
- Fasting: 95 mg/dL or higher
- One hour: 180 mg/dL or higher
- Two hours: 155 mg/dL or higher
- Three hours: 140 mg/dL or higher
You need two or more abnormal values on this test for a gestational diabetes diagnosis. A single elevated reading on the three-hour test does not meet the threshold, though your provider may still recommend dietary changes.
When Diet Alone Isn’t Enough
Most women with gestational diabetes can keep their numbers in range through changes to what and how they eat: smaller meals, pairing carbohydrates with protein and fat, and spreading food intake across the day. Walking for 15 to 30 minutes after meals also helps blunt post-meal spikes noticeably.
If your readings are consistently above target despite these changes, typically after one to two weeks of trying, your provider will likely recommend medication. Insulin is the most common option because it doesn’t cross the placenta. Some providers prescribe oral medications instead. The goal remains the same set of numbers: under 95 fasting, under 140 at one hour, or under 120 at two hours. Needing medication isn’t a failure. Some placentas simply produce more of the hormones that block insulin, and no amount of dietary adjustment can overcome that.
What A1C Means During Pregnancy
A1C measures your average blood sugar over the past two to three months. During pregnancy, it naturally runs a bit lower than usual because your body produces and cycles through red blood cells faster. The general target for A1C in pregnancy is 6 to 6.5%, with below 6% considered optimal if you can reach it without your blood sugar dropping too low. However, A1C is not the primary way gestational diabetes is monitored. Your daily finger-stick readings give a much more detailed and actionable picture than a single average over months.
What Happens After Delivery
For most women, blood sugar returns to normal soon after the placenta is delivered, since the placenta is the source of the hormones that were driving insulin resistance. But having gestational diabetes does increase your long-term risk of developing type 2 diabetes. Current guidelines recommend a follow-up glucose tolerance test between 4 and 12 weeks after delivery. This is a two-hour test using a 75-gram glucose drink.
On that postpartum test, a fasting level of 100 mg/dL or higher signals impaired fasting glucose, and a two-hour level of 140 mg/dL or higher indicates impaired glucose tolerance. A fasting reading of 126 mg/dL or higher, or a two-hour reading of 200 mg/dL or higher, meets the threshold for a diabetes diagnosis. Some hospitals now offer this screening before discharge, within the first two to five days after birth, as an alternative to the later outpatient visit.
Even if your postpartum test comes back normal, continued screening every one to three years is generally recommended, since the elevated risk of type 2 diabetes persists for years after a pregnancy affected by gestational diabetes.