[Glycemic thresholds in spontaneous abortion during the first trimester in pregnant women with insulin dependent diabetes].

BACKGROUND AND AIM: To evaluate the hypothesis that insulin-dependent diabetic (IDDM) pregnant women have a threshold of glycemic control during the first trimester of pregnancy for an increased risk of spontaneous abortion.

MATERIALS AND

METHODS

Seventy IDDM pregnant women were enrolled before the 9th week of gestation and monitored throughout pregnancy. Fifteen pregnancies (21.4%) led to spontaneous abortion within the first trimester (study group) and 55 (76%) continued until term (control group). In order to evaluate the differences between the study group and the control group variance analysis and Student's t-test were used for constant variables and chi 2 and Fisher's exact test for discrete variables; p < 0.05 was considered statistically significance.

RESULTS

Mean levels of glycosylated hemoglobin (HbA1c) and fructosamine at the initial prenatal visit were significantly higher in the study group (p < 0.03) compared to the control group. The threshold for an increased risk of spontaneous abortion in the first trimester was found to be initial concentrations > 8% for HbA1c and > 300 mmol/l for fructosamine.

CONCLUSIONS

Pregnant women suffering from IDDM with initial HbA1c levels higher than 8% and fructosamine > 3 mmol/l have an increased risk of spontaneous abortion in the first trimester of pregnancy. Below this threshold the risk of spontaneous abortion during the first trimester of pregnancy is similar to that for non-diabetic pregnant women.