Pregnant women with type 1 diabetes who have microalbuminuria, or increased levels of protein in the urine, are much more likely to deliver prematurely, according to a study from Denmark.
The researchers, publishing the results of their study in the October 2001 issue of Diabetes Care, say preterm delivery in these patients is caused by preeclampsia, a condition during pregnancy marked by high blood pressure combined with increased amounts of protein in the urine.
Pia Ekbom, MD, and colleagues conducted a study of 240 pregnant women with type 1 diabetes from January 1996 to February 2000 at the Obstetric Clinic at the National University Hospital in Copenhagen. The women, who were admitted before their 17th week of pregnancy, were categorized by their urinary albumin excretion (UAE, or level of protein in the urine). Normal UAE is considered to be less than 30 mg every 24 hours; microalbuminuria is considered to be 30 to 300 mg every 24 hours; diabetic kidney disease is considered to be more than 300 mg every 24 hours. Of the women studied, 85 percent (203) had a normal UAE rate, 11 percent (26) had microalbuminuria and 5 percent (11) had diabetic kidney disease.
In the diabetic kidney disease group, 64 percent of the women developed preeclampsia, 91 percent had a preterm delivery and 45 percent of the babies were smaller than normal. In the microalbuminuria group, 42 percent of the women developed preeclampsia, 62 percent had a preterm delivery and 4 percent of the babies were smaller than normal. Only 6 percent of the women with normal urinary albumin excretion developed preeclampsia, while 35 percent had a preterm delivery and 2 percent of the babies were smaller than normal.