Diabetes in Pregnancy

Please refer to your program's policies and procedures when caring for women with diabetes in pregnancy.

The following information is meant to guide current and new staff of Calgary Diabetes in Pregnancy Clinics. For referral information please visit our Calgary Diabetes Services page. 

1. What's Different in Diabetes in Pregnancy? 

Diabetes in pregnancy refers to pregnant patients with pre-existing type 1 or type 2 diabetes and those who develop gestational diabetes (GDM) during pregnancy. 

Similarities in management of diabetes between pregnant and non-pregnant patients: 

  • The use of lifestyle (nutrition, activity, stress management) to alter blood glucose levels, especially in GDM. 
  • The use of self blood glucose monitoring and record keeping. 
  • Instruction on how to identify and address glucose patterns. 
  • Multidisciplinary health-care teams. 

Differences in treating pregnant clients with diabetes: 

  • Only certain diabetes medications and insulin are safe or indicated to use in pregnancy. 
  • Target glucose levels are lower (may be modified/individualized by endocrinologist):
    • Fasting blood sugar < 5.3 mmol/L 
    • 1 hour after meals < 7.8 mmol/L 
    • 2 hours after meals < 6.7 mmol/L 
  • A1c done monthly during preconception and pregnancy in women with type 1 or type 2 diabetes. 
  • Not all continuous glucose monitoring devices are indicated for use in pregnancy. If used, they may require more frequent blood glucose checks to verify results.
  • Adjustment of insulin to avoid hypoglycemia, particularly when higher risk for hypoglycemia in first trimester and last month of pregnancy, in type 1 diabetes.
    • Technically, the glucose level for hypoglycemia during pregnancy is lower than that in non-pregnant diabetes patients. Verify with the endocrinologist what the acceptable level is for each patient.
    • Women with type 1 diabetes are at risk of hypoglycemia unawareness due to lower glucose targets and a blunting of counter-regulatory hormones (growth hormone and epinephrine). This is more likely in the first 18-23 weeks of gestation before insulin resistance develops.
    • While maternal hypoglycemia poses a significant safety risk for the woman, it does not increase the risk of congenital malformations in the baby.
  • Role of placenta in increased insulin resistance, usually starting after 20 weeks gestation (resulting in increased insulin needs).
    • Individuals with type 2 diabetes and GDM may require 2-3 times (or more) insulin in the third trimester than earlier in the pregnancy. This may result in some patients being on 20-40 units per meal bolus early in the pregnancy and up to 90-120 units per meal bolus by the end of the pregnancy.
    • Concentrated insulin formulations may be considered for higher meal doses such as Humalog/lispro 200 u/ml. Entuzity (500 u/ml) is also available although used rarely.
    • We generally suggest that large insulin doses be given in split injections for better absorption once a single dosage exceeds 50 units of insulin (for 100 u/ml formulations).
  • More frequent follow-up with educator and/or endocrinologist. 
  • More frequent insulin adjustments, often sooner than every 2-3 days. 
  • Different complications for mother and infant. Poor glycemic control in pregnancy is a risk for still birth and potential for worsening of diabetes complications in the mother.
  • Role of culture and beliefs in contraception, pregnancy, birth and postpartum care.

Similarities and differences in nutrition management of pregnant patients with diabetes: 

  • Distribution of carbohydrates across the day. 3 meals and 3 snacks are usually recommended, including a bedtime snack.
  • Detailed carbohydrate counting skills for most women with type 1 diabetes.
  • Promotion of healthy weight gain during pregnancy.
  • Nutrition specific recommendations for pregnancy (Topics Catalogue: Nutrition Guidelines for Pregnancy) such as the following:
    • Helping women manage possible gastric discomfort during pregnancy such as nausea, vomiting, heartburn, or constipation
    • Adequate nutrition for healthy fetal development. Incorporation of appropriate calories, folate, iron, calcium and other necessary vitamin and mineral requirements for pregnancy.
    • Counselling on food safety during pregnancy. 

2. Basic Obstetrical Knowledge

GPA

When reading a prenatal chart you will see the abbreviation GPA indicating a woman's obstetrical history.

  • G- Gravida: number of pregnancies, including present pregnancy
  • P- Para: number of live births
  • A- Abortus: number of miscarriages/abortions

Example: G3, P2, A1, means she has had 3 total pregnancies with 2 live births and 1 abortion/miscarriage.
Example: G4, P3, A0, means she is pregnant for the fourth time with 3 live births. Once she gives birth she will be G4, P4, A0.