Intensive control of high blood pressure (hypertension) leads to improved pregnancy outcomes in women with type 1 diabetes and kidney disease, Danish researchers report in the journal Diabetes Care.

“Diabetic women with kidney involvement have an increased risk of complications in pregnancy leading to preterm delivery,” lead investigator Dr. Lene Ringholm Nielsen told Reuters Health. “This paper describes how intensive antihypertensive treatment in pregnant diabetic women reduces the risk of complications in pregnancy.”

Nielsen and colleagues at Rigshospitalet, Copenhagen prospectively studied 117 pregnant women with diabetes. Antihypertensive therapy was used as needed to maintain blood pressure below 135/85 mm Hg and normal levels of albumin (a protein) in the urine (below 300 mg per 24 hours).

Treatment was given to 14 of 100 women with normal levels of albumin in the urine, to 5 of 10 with slightly increased levels of albumin, and to all 7 women with diabetes-related kidney disease. The average systolic blood pressure (the top number in the reading) for these three groups was 120, 122, and 135 mm Hg, respectively. There were no differences in average diastolic pressure (the lower reading) or in hemoglobin A1C level - a test that indicates blood sugar level, among the groups.

There were three cases of preeclampsia, all in women with diabetic kidney disease. Preeclampsia is a potentially dangerous condition of pregnancy that is characterized by high blood pressure, protein in the urine, and fluid retention.

The incidence of preterm delivery was 20 percent in women with normal or slightly increased albumin levels and 71 percent in women with diabetic kidney disease.

Average birth weights were similar in the normal or slightly high albumin levels, 3540 grams and 3430 grams, respectively, but lower among women with diabetic kidney disease - 2765 grams.

However, say the investigators, compared with earlier studies that used a “less stringent” strategy to control blood pressure, albumin levels and blood glucose levels, the birth weights in this study were higher and the length of pregnancy longer.

Thus, concluded Nielsen, the results suggest that “early control of hypertensive problems in diabetic pregnancy leads to a higher number of infants born to term.”

SOURCE: Diabetes Care, 2008.