Pregnancy And Diabetes


Gestational diabetes (GDM) is defined as diabetes diagnosed during pregnancy. By definition, GDM resolves as soon as the baby is born. If you continue to have diabetes after you deliver your baby then, in virtually all cases, you have type 2 diabetes.  Your baby will NOT be born with diabetes.

Although the "best" way in which pregnant women should be tested for gestational diabetes is currently the subject of much debate, testing is typically performed during the 24th-28th weeks of pregnancy by drinking a sugar-rich product (containing 50 grams of sugar) and then, an hour later, having your blood glucose level measuredl. If the blood glucose level is above 7.7 mmol/L this is considered abnormal, but in and of itself does not make a diagnosis of GDM. Rather a confirmatory test is then done wherein you would drink a sugar-rich product (containing 75 gms of carbohydrate) and have your blood glucose level checked before then 1 and 2 hours thereafter. If two or more of the blood glucose readings are high then a diagnosis of GDM is made.

You are at increased risk of developing GDM if you have risk factors for type 2 diabetes such as having a family history of diabetes or being overweight. Nonetheless, it is not uncommon for women with GDM to have no risk factors for diabetes.

What is the importance of GDM? Well, first of all, most moms with GDM have otherwise uneventful pregnancies and healthy babies. That is, everything goes just fine. But, potentially, GDM can lead to the fetus being large (if the mom's blood sugar level is high then sugar goes from the mom into the fetus-sort of like overfeeding the baby while it's still inside the uterus) which can make delivery more difficult. There is also an increased risk of the baby being born with low blood sugar (usually easily treated by giving the baby sugar water to drink) which generally is not a problem after a day or two. Other complications seldom occur.

GDM is treated by:

  • Following a special nutrition plan (as taught to you by a registered dietitian)
  • Staying physically active
  • Taking insulin if, depsite nutirition and staying physically active, your blood glucose readings remain above target. (Target blood glucose is less than 5.3 before breakfast, less than 7.8 one hour after meals, less than 6.7 two hours after meals.)  (Oral medications like glyburide and metformin are less proven to be safe during pregnancy than is insulin.)

After you deliver you can return to a conventional (but healthy, of course) diet.

Within a few months of delivering you need to have a glucose tolerance test to ensure you no longer have any blood sugar problems.

Of great importance, if you have had gestational diabetes then this indicates that you are at high risk of later developing type 2 diabetes. Therefore, if you have had GDM you should:

  • Lead as healthy a lifestyle as possible. If you achieve and maitain a healthy weight and you exercise regularly you will reduce your risk of developing type 2 diabetes by 60 percent or more.
  • Be tested for diabetes annually so that if you've developed type 2 diabetes it will be discovered sooner rather than later.
  • Be tested for diabetes before trying to conceive in the future so that if you have developed type 2 diabetes it can be treated before you get pregnant.

You can learn more about screening for type 2 diabetes after having had gestational diabetes by reading the wonderful tools that the CDA created under the guidance of Jennifer Snyder:

  • You'll find the tool for health care professionals here.
  • You'll find the tool for women who have had gestational diabetes here.


If you are a woman with type 1 or type2 diabetes and you are contemplating pregnancy then it is imperative that you have excellent blood glucose control before you withdraw contaception.

If you have insufficient blood glucose control at the time you get pregnant or during your first trimester (when the fetus's organs are forming) then you will have up to a 30 percent chance of having a baby with a malformation such as damage to the brain, heart, or spinal cord. You also will be at much higher risk of having a miscarriage.

This is what you should do before you withdraw contraception:

  • Speak to your diabetes specialist. Trust me, they'll want to know of your plans so that they can work with you to do everythng possible to help you have a healthy pregnancy. (I tell my female patients that are looking at pregnancy to let me know at least 6 months in advance of when they want to withdraw contraception.)
  • Have an A1C of 7 or less.
  • Have your eyes checked by a skilled eye professional.
  • Have your kidney function checked by a blood test (creatinine, eGFR) and urine test (albumin/creatinine ratio).
  • Take folic acid 5 mg daily beginning 3 months before conception and taken until about 12 weeks into the pregnancy (at which time the dose can be reduced to about 1 mg daily which should be continued until you've completed breast feeding).
  • Stop drugs (like ACE inhibitors, ARBs, statins) that are potentially dangerous to a fetus.
I realize that you may be reading this and and feel terrified because you are pregnant and you haven't - for whatever reason - done all the things I mention in the preceding list.  If so, then although there will be a number of very real and very great concerns, you should also be aware that many women have been in a similar situation yet things worked out okay. Make sure you get in touch with your diabetes specialist as soon as possible so that your particular situation and needs can be addressed.