What Causes Diabetes During Pregnancy?

Glucose, a sugar that results from the digestion of food, is the body's main nourishment. During pregnancy, your body also supplies your baby with glucose, which is delivered through the placenta and is your baby's only source of nourishment.

The placenta also makes certain hormones to help the baby develop. But these hormones make it harder for your body to use insulin. About halfway through pregnancy, the placenta increases its production of these anti-insulin hormones.

If your body makes too many anti-insulin hormones, they can block the movement of glucose from your bloodstream into your cells. This is called insulin resistance. At the same time, your pancreas may not be able to produce enough insulin. When too much glucose builds up in your bloodstream, diabetes can result.

Who Is At Risk?

Several factors increase your chances of developing diabetes during pregnancy. These include:

• A family history of diabetes
• Previously giving birth to a stillborn baby or to a baby weighing more than nine pounds
• Obesity
• Being over age 25

How Do I Know If I Have Diabetes?

Gestational diabetes has no obvious symptoms. The American Diabetes Association recommends that all women be screened for gestational diabetes between the 24th and 28th week of pregnancy, or sooner if you have a history of gestational diabetes or other risk factors.

Screenings include:

• Blood glucose test - A sweet, specially prepared glucose mixture is swallowed. One hour later, a blood sample is taken and tested to determine how much glucose is still present. If your blood glucose level is above 140 mg/dl (milligrams per deciliter), your doctor will recommend a glucose tolerance test.
• Glucose tolerance test - You follow a special diet for three days, then fast for eight hours. Before you are permitted to eat or drink anything, a blood sample is taken and tested. A glucose drink is consumed, and a blood sample is taken every hour for three hours. If your blood glucose is in the abnormal range, gestational diabetes is diagnosed.

What If I Already Have Diabetes?

Women with pre-existing diabetes used to be warned against pregnancy because they were more likely to have a baby with birth defects. Today, with careful planning and preconception care, diabetic women have as much chance as non-diabetic women of having a problem-free pregnancy and a healthy baby.

Pregnancy can, however, worsen some long-term diabetes complications. Before stopping birth control, it's a good idea to have the following evaluations:

• An eye exam
• Kidney function test, which involves providing a blood and/or urine sample
• Blood pressure reading
• Pelvic exam
• Assessment for heart disease
• Hemoglobin A1c test (a blood test that shows whether your blood sugar has been normal over the past three to four months). If the hemoglobin A1c value is very high when you get pregnant, your baby has an increased chance of a birth defect when born.

How Does Diabetes Affect Pregnancy?

In women with gestational diabetes and type 2 diabetes, the sugar (glucose) in your blood directly affects the size of your baby. If your blood sugar level is high, the baby gets too much nourishment and overgrows. This can lead to a condition called macrosomia or "fat" baby. Macrosomia causes problems for both you and your baby.

What Are The Risks To The Baby?

Babies who get too much sugar (glucose) from their mother's blood accumulate fat around the shoulders and trunk. That can make them too difficult to delivery vaginally. Your doctor may recommend delivering the baby early.

Other risks associated with gestational diabetes and type 2 diabetes include:

• Damage to the baby's shoulders during delivery
• Low blood sugar in the baby at birth
• Higher risk for obesity and type 2 diabetes later in life for the baby
• Jaundice (a yellowish discoloration of the skin) two to three days after birth

Risks associated with type 1 diabetes include:

• Low blood sugar at birth
• Breathing problems at birth
• Jaundice two to three days after birth
• Increased chance of major birth defects

What Are The Risks To The Mother?

Risks associated with gestational and type 2 diabetes include:

• Possible need for cesarean delivery
• Pregnancy-related high blood pressure and swelling of the hands and feet
• Urinary tract infections
• An increased chance of developing diabetes later in life or in a subsequent pregnancy

Risks associated with type 1 diabetes include:

• Premature labor and delivery
• Possible need for cesarean delivery
• Pregnancy-related high blood pressure and swelling of the hands and feet
• Urinary tract infections
• Buildup of ketones (harmful acids) in the blood
• Possible worsening of eye disease
• Possible (reversible) progression of kidney disease

How Can I Avoid Complications?

Problems associated with diabetes in pregnancy are manageable and preventable. The key to prevention is careful control of your blood sugar as soon as gestational diabetes is diagnosed.

• Women with pre-existing diabetes should get their blood sugar under control three to six months before conception, to lessen the risk of birth defects.
• Gestational diabetes, which starts later in pregnancy, does not cause birth defects.

Will My Baby Be Healthy?

During pregnancy, several tests will be done to make sure your baby is developing properly and to help predict the time of delivery.

• Ultrasound - This test involves passing a special wand over the skin of the abdomen. Sound waves are transmitted into the body and bounce back, creating an image that shows the growth and development of the baby.

• Alpha-fetoprotein test - This is a blood test that detects a particular protein produced by the baby's liver. Abnormal levels of alpha-fetoprotein (AFP) indicate a high risk for certain types of birth defects.

• Amniocentesis - In this test, a long thin needle is inserted into the abdomen and a sample of amniotic fluid (the fluid that surrounds the baby within the uterus) is taken. Cells in the fluid help doctors determine if the baby's lungs are mature enough to withstand early delivery.

• Non-stress test - A fetal monitor, strapped to the mother's abdomen, records the baby's heart rate for a short period of time. This reading helps doctors assess the health of the baby in the last weeks of pregnancy.

• Fetal monitoring - During labor and delivery, a fetal monitor keeps constant track of the baby's heart rate in order to detect the first indications of distress.

Managing Diabetes During Pregnancy

The goal in treating diabetes is to keep blood sugar levels as normal as possible. That usually involves:

• Daily blood glucose monitoring
• Taking insulin
• Following a special diet
• Following an exercise program

It's normal to feel stressed during pregnancy. Diabetes creates additional stresses. You have to see your doctor more often than women without diabetes, follow a special diet, and monitor your blood sugar several times per day. Here are some strategies for coping.

• Listen to your body.
• Learn to ask for help.
• Enlist the support of family, friends, or other women facing the same concerns.
• Make time for regular exercise.
• Keep your sense of humor.
• Take good care of yourself.
• Learn a relaxation or meditation technique.
• Be positive.

During your pregnancy, contact your doctor if you have:

• Vaginal bleeding
• Sharp back pain
• Burning or painful urination
• An infection
• Dizziness or fainting
• Rapid weight gain
• Swelling in the hands, face or feet
• Severe nausea with high blood sugar
• A decrease in your baby's movement