Strategies for reducing the frequency of preeclampsia in pregnancies with insulin-dependent diabetes mellitus

The object of this study was whether improving glycemic control and maintaining normal glycosylated hemoglobin (HbA(1c)) through pregnancy can reduce the frequency of preeclampsia. One hundred and twenty-three complete medical records of pregnant insulin-dependent diabetics (IDDM) managed at Yale-New Haven Hospital from 1983 to 1993 were reviewed. Serial HbA(1c) measurements and the occurrence of preeclampsia were recorded. Based on the change of HbA, values through the pregnancy, glycemic control was categorized into four groups: group 1, high to normal; group 2, high to high; group 3, normal to normal; group 4, normal to high. The association between HbA(1c) change and the incidence of preeclampsia was analyzed by chi-square test and Fisher's exact test. Among 123 IDDM pregnancies, 40 (32.5%) developed preeclampsia. High HbA(1c) levels at any time in IDDM pregnancies were associated with an increased incidence of preeclampsia (group 1 or 2 or 4 versus group 3). Reducing HbA(1c) by improving glycemic control both before and during pregnancy resulted in a significantly lower incidence of pre-eclampsia (group 3 versus groups 1+2+4, p <0.05). The best strategy for reducing the frequency of preeclampsia in IDDM pregnancies is by improving glycemic control before pregnancy.