Given that approximately half of all pregnancies in the United States every year are unplanned, birth control is an important consideration for all sexually active women at risk of becoming pregnant. In the case of women with diabetes, however, precision in family planning is even more crucial because of the effect of high blood glucose on the developing fetus.
“There’s a very close correlation between blood sugar level and the incidence of birth defects in the offspring of women with diabetes,” says Jo M. Kendrick, MSN a clinical instructor at the University of Tennessee Graduate School of Medicine’s Department of Obstetrics and Gynecology and author of Diabetes in Pregnancy (a guide for nurses). According to Kendrick, “Anytime you have a[n HbA1c] level of 7% or greater, there’s an increased risk of birth defects in the offspring or, as it rises even higher, an increased risk of miscarriage.” The HbA1c, or glycosylated hemoglobin, test gives an indication of average blood glucose control over the previous 2–3 months. People who don’t have diabetes generally have an HbA1c level between 4% and 6%.
Because of these risks, women with diabetes are advised to bring their blood glucose levels as close to normal as possible before attempting to conceive. In addition, any woman with diabetes who is considering having a baby should have a physical exam and a laboratory assessment to look for any evidence of vascular (blood vessel) disease, since pregnancy can put a great deal of stress on the vascular system. Having eyes and kidney function assessed is another important part of preconception care for women with diabetes.
According to Kendrick, “We very strongly encourage women to get an eye exam to make sure that they don’t have any retinopathy, an EKG [electrocardiogram] if they’ve had diabetes for more than 10 years [to check for heart disease], and a 24-hour urine test to assess renal function.” A psychosocial evaluation is also recommended. “Pregnancy in women with either Type 1 or Type 2 diabetes can be very stressful, not only because of the demands of pregnancy, but also because of the additional demands of diabetes control” says Kendrick.
All women considering pregnancy — with diabetes or without — should start taking a daily prenatal vitamin supplement that includes 400 micrograms of folic acid before conception occurs. This level of folic acid intake has been shown to help prevent the types of birth defects called neural tube defects.
For women who do not wish to become pregnant, reliable birth control is a must. “I certainly think that some methods are better than others, but that’s a decision that a woman and her partner should make in conjunction with a health-care provider,” Kendrick says. “I wouldn’t encourage natural family planning if a woman’s glycemic control weren’t excellent, and I’d be concerned about methods with a higher failure rate, such as barrier methods. But if a woman is maintaining good glycemic control and she prefers these methods, there’s no reason why she shouldn’t be able to use them.”
Kendrick is a proponent of methods that require infrequent administration, such as the NuvaRing, the Mirena intrauterine device, the Ortho Evra patch, and Depo-Provera contraceptive injections. “With all the other things that women have to think about when they have diabetes, contraception should be easy.” She also encourages women with diabetes to keep a current prescription for emergency birth control, as long as they do not have any special conditions, such as unexplained vaginal bleeding, that make the use of emergency contraception unsuitable.