Pregnancy and Diabetes: Understanding Hypoglycemia in the First Trimester

Patient Expert

Starting at any point between six to 10 weeks of pregnancy, it is likely your body is going to start producing some of its own insulin again. Yes! You read that correctly. Don't be surprised if you've never been taught this by your endocrinologist or CDE, but it ought to be taught to every woman considering pregnancy or currently pregnant: Your body, which hasn't been able to suc-cessfully produce insulin since shortly before you were diagnosed, will actually produce insulin during pregnancy.

There are two reasons why this happens:

As soon as you become pregnant, your body begins producing more progesterone, which is what causes that initial rise in your blood sugars due to insulin resistance in the first few weeks of your pregnancy.

"Progesterone is initially produced by the corpus luteum, a component of the ovaries," explains Jennifer C. Smith, RD & CDE at Integrated Diabetes, and co-author of Pregnancy with Type 1 Di-abetes. "However, around weeks 7 through 9, this progesterone production suddenly drops as the placenta takes over production of the progesterone, and thus your insulin resistance decreases as well."

"Some women experience a decrease in insulin needs that lasts for about 4 weeks, and others may experience this decrease for a shorter amount of time, or the decrease may be more subtle rather than dramatic."

The second reason for low blood sugars in the coming weeks is that during your first trimester of pregnancy, the immune system actually starts to "back off" in order to protect your growing em-bryo.

Like all people diagnosed with type 1 diabetes, explains Smith, your immune systems are usually constantly attacking and destroying the beta cells residing in your pancreas that are responsible for the production of insulin.

That means that as soon as the immune system backs off, there isn't as much of an attack on those remaining beta cells, and they can actually start producing a bit of insulin which will bring injected or pumped insulin needs down. And poof! We become semi-insulin-producing type 1 diabetics. It's an amazing, awesome thing.

However, you won't start producing enough insulin to totally cover your body's needs, which means you're still going to be doing all of your daily diabetes management work ― you'll just need less insulin.

Smith emphasizes that you'll notice the amazing decrease in insulin needs through one or several of these symptoms:

  • Treat a low blood sugar (mild or severe), watch it rise to a nearly "perfect" level between 70 and 100 mg/dL (3.3 to 5.5 mmol/L), and then within an hour or so later, watch it start to drop again.
  • Between meals, when no insulin doses for food are on-board, your blood sugar will sud-denly begin to plummet. This can happen several times within one night or day until doses are reduced.
  • Take your normal insulin dose for a meal, watch your blood sugar "fat-line" at/near non-diabetic levels on your CGM or glucose meter, then watch it plummet about an hour after eating.

As women with type 1, we're not really used to insulin coming from anywhere besides our own syringes, pens, or pumps.

How much insulin will you produce?

"This is a tricky question because the answer is different for everyone," explains Smith.

The insulin production will be gradual at first, and the amount of carbohydrates you can eat without taking any insulin is going to vary greatly from one woman to another.

Don't be concerned if the amount of carbs you can eat isn't as much as another woman's: it has absolutely no implication on the health of your baby or your health as a woman with diabetes.

Some women find they can eat 10, 15, or even 20 grams of carbs without taking additional insulin. And others find that they still need plenty of insulin for meals, but they're taking significantly less background insulin.

Like many other aspects of living with type 1 diabetes, there is no one-size-fits-all approach to ad-justing your current insulin doses for the sake of this change in hormones and newfound natural insulin production. And it gets even more fun when that insulin production increases very gradual-ly over the course of a week or even two weeks, rather than all in one day or two. You'll find your insulin needs start to increase again around week 16 due to baby's increasing growth and your increasing hormones. All very normal and healthy things!

Meanwhile, enjoy getting an amazing kind of "help" that no one else could have possibly provided except for your own pancreas (and thankfully, your very reluctant immune system).

See more helpful articles:

Gestational Diabetes and Congenital Heart Defects

9 Facts About Childbirth With Type 1 Diabetes

10 Ways to Have a Healthy Pregnancy With Diabetes