How Diabetes Affects Pregnancy
Pregnancy is a time of big changes for any woman. These changes affect your
blood sugar levels. Sometimes, a woman who is pregnant develops diabetes during
the course of her pregnancy. This is called “gestational diabetes.” Gestational
diabetes begins during pregnancy, and usually goes away after the baby is born.
About 3 percent of pregnant women develop this condition. The blood sugar
becomes too high, and if you don’t bring it under control, problems for both you
and your baby can result.
The same is true for women who already had diabetes before they were pregnant.
If you have type 1 diabetes, your need for insulin will probably increase when
you’re pregnant. If you have type 2 and have been controlling it by diet, you
may be able to continue in this way. But if you’ve been taking pills to control
your blood sugar, you’ll have to switch to insulin injections when you’re
pregnant because the pills can cause birth defects. You healthcare team will be
able to help you with this big change.
How blood sugar affects baby and mother
Here are some of the problems high blood sugar can cause during pregnancy:
- High blood sugar levels and ketones pass through the placenta to the baby.
In large amounts, ketones can be poisonous. This increases the chances of
- The baby’s organs begin forming early in pregnancy, before you may even
know you’re pregnant. High blood sugar levels can have a negative effect on
these growing organs.
- When the mother’s sugar level is high, the baby consumes too much sugar
and can become too big. This makes giving birth harder—for the mother and the
- When babies consume too much sugar, their pancreas produces extra insulin.
After birth, the pancreas may continue to produce insulin, so babies are at
risk for developing low blood sugar.
If you already have diabetes…
If you’re thinking about becoming pregnant soon, talk about your plans with your
healthcare team. If you don’t have a healthcare team, or if you haven’t
connected with them in a while, now is a good time. Members of the team should
- Diabetes educator
- Eye doctor
The team can give you a thorough assessment of your health and
recommendations about how to get yourself in the best possible condition for
pregnancy. They can also help you plan ahead by explaining how pregnancy will
affect your diabetes. For example, when you’re pregnant, you’ll probably need to
test you blood sugar more frequently than you currently do. Your healthcare team
may recommend that you get in that habit now.
Getting tested for gestational diabetes
When you’re pregnant, your doctor is likely to perform the following tests to
screen for gestational diabetes:
Glucose screen: This is performed during the second trimester. For this
test, you’ll either have your blood sugar level checked after 12 hours of
fasting or you will drink a very sweet drink. An hour later, your blood will be
drawn. If the result is positive, then you’ll probably have the glucose
Glucose intolerance test: For this test, you eat normally the day before
and do not eat during the night. Before the test, you’ll have a sweet drink.
Then your blood will be drawn once an hour for 3 hours. (It’s a good idea to
have a book or magazine with you when you have this test done.)
If you have gestational diabetes, your doctor or other healthcare provider will
talk with you about your treatment plan. You’ll need to work out a food plan and
an exercise routine, and there’s a good chance you may have to take insulin for
the rest of your pregnancy. Your healthcare team will help you all along the
way, so that you have an excellent chance of keeping your blood sugar in a
healthy range until your baby is born.
American Diabetes Association; Diabetes Forecast, December 1997;
National Institute of Diabetes and Digestive and Kidney Diseases.