Checking Your Blood Sugar During Pregnancy with Type 1 and Type 2 Diabetes


Editor’s note: There is no “one-size-fits-all” approach to diabetes and insulin management during pregnancy. Talk to your healthcare team before making any changes in your diabetes regimen, and check your blood sugar often! This educational content was made possible by Roche.

Managing your blood sugars during pregnancy is not a simple task—especially if you’re taking insulin. Here, we’ll discuss when and why it’s so important to check your blood sugar levels frequently and how your insulin needs and diabetes management can change throughout your pregnancy.

Recommended times of day to check your blood sugar during pregnancy

The point of checking your blood sugar frequently throughout your pregnancy is to get information. Your blood sugar levels give you information that tells you whether your insulin or other medication doses need to be adjusted. 

Uploading your blood glucose meter data to an app like mySugr can help you look at your blood sugar trends, spotting what times of day you tend to be higher or lower than your goal range—also referred to as “time-in-range.”

It is normal and expected for your insulin doses to change throughout your pregnancy because increasing pregnancy hormones impact your sensitivity to insulin.

Checking your blood sugar at these times of day can help you gather the information you and your healthcare team need to make thoughtful adjustments in your diabetes management regimen. Here is what (and when) you and your provider will likely monitor throughout your pregnancy:

  • Fasting: as soon as your wake up 
  • Pre-prandial: right before you eat a meal or snack
  • Post-prandial: about two hours after you eat a meal or snack
  • Before bed: right before going to bed for the night
  • Midnight or 2 a.m.: A few overnight blood sugar checks can help pinpoint adjustments needed to ensure you’re in your goal range while sleeping, and by the time you wake up in the morning.

Before pregnancy

Research has found that your blood sugar levels during the six months before becoming pregnant have a significant impact on your child’s risk of developing congenital disabilities.

It is highly recommended if you can plan your pregnancy, spend at least six months to a year preparing your body by learning how to manage tighter blood sugar levels!

Take this time to check your blood sugars frequently and compare those numbers to what your A1c implies. (If you use a continuous glucose monitor, you can also look at your “time-in-range.”) 

During pregnancy, the goal is an A1c of below 7.0 percent. Here, you can see what that looks like as an actual blood sugar level range. 

The American Diabetes Association offers this A1c/ eAG calculator to easily translate your A1c results to an eAG or Average Blood Glucose mg/dL.

A1c Average Blood Glucose mg/dL Range of BG mg/dL
12% 298 240 – 347
11% 269 217 – 314
10% 240 193 – 282
9% 212 170 –249
8% 183 147 – 217
7% 154 123 – 185
6% 126 100 – 152

Spend this time working with your healthcare team to adjust your insulin and medication dosages and your habits around food and exercise to maintain blood sugars within your goal range.

During pregnancy: what to expect in each trimester

The trickiest thing about blood sugar management during pregnancy—besides the overwhelming pressure to suddenly be perfect—is that your insulin needs can change every few weeks or several times within two weeks. 

It’s all about the hormones.

  • First trimester: Before you’re even able to confirm you’re pregnant, you’ll likely notice your blood sugars running a bit higher, calling for an increase in your basal/background insulin. About halfway through the first trimester—around six to eight weeks—however, your insulin sensitivity can skyrocket. Some research also suggests your body successfully starts producing some insulin again because your immune system calms down to accommodate for the growing fetus. As your immune system calms itself, it potentially stops attacking your beta-cells as vigorously. Some women can eat snacks or meals without any bolus/mealtime insulin during these few weeks, while others may only see a slight decrease in insulin needs.
  • Second trimester: Bit by bit throughout this trimester, the intense drop in your insulin needs during the first trimester will gradually lessen as the fetus grows and your hormone levels rise. By the end of this trimester, both your basal/background and your bolus/mealtime insulin needs will have likely increased substantially compared to non-pregnant insulin doses.
  • Third trimester: Whoa, mama, this trimester is all about insulin resistance. As both you and the fetus gain weight and pregnancy hormones continue to increase, your insulin needs will likely need to increase, too. You’ll also find you need to take your insulin much earlier before eating to prevent post-meal spikes. It’s important to help counter this increasing insulin resistance with thoughtful choices around food and daily physical activity—especially daily walks. 

The only way to know if your insulin needs or other medications need an adjustment is by checking your blood sugar frequently! Take good notes and consider using an app like mySugr to help you spot what times of day you’re either in or out of your goal blood sugar range!

This content mentions Roche, an active partner of Beyond Type 1.
News coverage by the Beyond Type 1 team is operated independently from any content partnerships. Beyond Type 1 maintains full editorial control of all content published on our platforms.

WRITTEN BY Ginger Vieira, POSTED 01/05/22, UPDATED 10/09/22

Ginger Vieira is an author and writer living with type 1 diabetes, celiac disease, fibromyalgia and hypothyroidism. She’s authored a variety of books, including “When I Go Low” (for kids), “Pregnancy with Type 1 Diabetes,” and “Dealing with Diabetes Burnout.” Before joining Beyond Type 1 as digital content manager, Ginger wrote for Diabetes Mine, Healthline, T1D Exchange, Diabetes Strong and more! In her free time, she is jumping rope, scootering with her daughters, or walking with her handsome fella and their dog.