Managing Diabetes During Pregnancy

Florence Brown, M.D., Co-Director, Joslin-Beth Israel Deaconess Medical Center Diabetes and Pregnancy Program; Instructor in Medicine, Harvard Medical School;
Tamara Takoudes, M.D., Co-Director, Joslin-Beth Israel Deaconess Medical Center Diabetes and Pregnancy Program; Instructor in Medicine, Harvard Medical School

According to the Centers for Disease Control and Prevention, about 1.85 million women of reproductive age have diabetes, and about 500,000 of them do not know it.

As these numbers continue to rise, it is increasingly important for women with diabetes to achieve normal blood glucose levels before they become pregnant because if women have poorly controlled diabetes going into a pregnancy, they are at much higher risk for serious fetal complications.

Changing hormones in the body during pregnancy cause blood glucose levels to rise, and high blood glucose levels in early pregnancy (within the first four to six weeks) can result in a 30 to 40 percent chance of having a baby with a birth defect compared to a 2 percent risk in women whose diabetes is in excellent control.

Women with type 1 diabetes or type 2 diabetes are also at higher risk for:

  • Large birth weight babies, resulting in more Cesarean deliveries and increased complications during delivery
  • Premature births or fetal death
  • Pre-eclampsia: a dangerous surge in blood pressure associated with protein in the urine
  • Diabetic retinopathy: damage to the retina caused by high glucose levels
  • Nephropathy: diabetic kidney disease
  • Severe hypoglycemia: episodes of low blood glucose that can result in confusion or unconsciousness

Ensuring a healthy pregnancy

The good news is that women with uncomplicated diabetes who keep their blood glucose levels in a normal range before and during pregnancy have about the same chance of having a successful pregnancy as women without diabetes.

The Joslin-Beth Israel Deaconess Pregnancy Program recommends the following blood glucose goals and medical assessments before pregnancy:

  • Fasting and pre-meal blood glucose: 80-110 mg/dl
  • Blood glucose one hour after meal: 100-155 mg/dl
  • A1C, a blood test that measures average blood glucose over two to three months: less than 7 percent
  • Review of diabetes and obstetrical history
  • Eye evaluations to screen for and discuss risks of diabetic retinopathy
  • Renal, thyroid, gynecological and cardiac evaluations

Once pregnant, women should monitor their blood glucose levels four times a day (before breakfast and one hour after every meal.) Fasting and pre-meal glucose levels should be between 60 and 99 mg/dl, and one-hour post-meal readings should be between 100 and 129 mg/dl.

Other recommendations to ensure a successful pregnancy: (sidebar)

  • See your diabetes provider every one to four weeks
  • Have your A1C level checked every four to eight weeks
  • Meet with a certified diabetes educator and registered dietitian, as needed
  • Follow USDA diet guidelines, including folic acid supplements
  • Do some physical activity, as directed by your obstetrician
  • Always check your blood glucose before driving (due to an increased risk of severe hypoglycemia)

Gestational diabetes

The other form of diabetes that affects women is gestational diabetes, which develops during pregnancy. Mirroring the epidemic of type 2 diabetes, rates of gestational diabetes are also on the rise in the United States, particularly in the African American, Hispanic, American Indian and Alaskan native communities.

Gestational diabetes usually develops between the 24th to 28th week of pregnancy and affects about four percent of all pregnancies. This condition typically ends after birth; however, these women have a 50 percent risk of developing type 2 diabetes over the next 10 to 20 years.

Factors that increase a woman’s risk of developing gestational diabetes:

  • Obesity
  • Previous history of gestational diabetes
  • Sugar in the urine
  • A parent or sibling with diabetes
  • Polycystic ovary syndrome or other glucose metabolism problem
  • Previous pregnancy in which the baby weighed more than nine pounds at birth

If you fall into any of these categories, you should be screened early, within the first tri-mester, for gestational diabetes. Women who find out that they have gestational diabetes should see a nutritionist and diabetes nurse educator, as diet is the first line therapy.

With careful diabetes management, women can and do have successful pregnancies and healthy babies.

This article originally appeared in the Special Diabetes Insert in the Nov. 13, 2006 issue of TIME Magazine.