264: Pregnancy outcome in gestational diabetes controlled with glyburide: is it just the glucose?

Abstract

Poor control of gestational diabetes (GDM) is associated with adverse neonatal outcome. However, little is known about other factors that may affect neonatal outcome in women with GDM that attain good glycemic control with glyburide therapy. This is a prospective observational study of GDM patients treated with glyburide according to our previously described protocol (NEJM, 2000). Neonatal outcome was determined in women who were treated with glyburide and who achieved good glycemic control (mean blood glucose ≤ 105 mg/dl), and included the following: macrosomia (birth weight ≥ 4000 g), LGA (birth weight ≥ 90th% for gestational age), SGA (birth weight <10th% for gestational age). Patients who achieved good glycemic control were further categorized according to their mean blood glucose values (≤85, 86-95, and 96-105 mg/dL) and the outcomes of interest were determined in each sub-group. From 2004-2009, 567 GDM patients were treated with glyburide, and 431 of these (76%) achieved good glycemic control. Neonatal outcomes are depicted in the table below. There were no significant differences between groups with respect to neonatal growth abnormalities. Multiple logistic regression analysis determined that birth weight percentile was not associated with maternal BMI, severity of GDM, or maternal blood glucose at delivery, but was positively associated with the ultimate glyburide dose. Mean blood glucose of patients who delivered an AGA infant was 101±13 mg/dl compared to 105±13 mg/dl in those who delivered an LGA infant (p=0.06).Tabled 1Rates of Growth Abnormalities by Mean Maternal Glucose in Well Controlled GDM≤ 85mg/dl86-95mg/dl96-105mg/dlLGA %14.38.413.7Macrosomia %5.93.18.1SGA %7.17.78.6 Open table in a new tab Women with GDM whose mean blood glucose falls below the threshold of good control do not have an increased rate of LGA infants compared to the general population, regardless of the actual mean glucose achieved. Once this target is attained, other pre-existing maternal factors do not seem to affect the rate of fetal growth.