Modified Therapy for Gestational Diabetes Using High-Risk and Low-Risk Fetal Abdominal Circumference Growth to Select Strict Versus Relaxed Maternal Glycemic Targets

doi:10.2337/dc07-s216

Modified Therapy for Gestational Diabetes Using High-Risk and Low-Risk Fetal Abdominal Circumference Growth to Select Strict Versus Relaxed Maternal Glycemic Targets

Siri L. Kjos, MD1 and
Ute M. Schaefer-Graf, MD, PHD2

¹Department of Obstetrics and Gynecology, University of California, Los Angeles, Harbor UCLA Medical Center, Torrance, California
²Department of Obstetrics, Vivantes, Berlin, Germany

Address correspondence and reprint requests to Siri Linda Kjos, MD, Department of Obstetrics and Gynecology, Harbor UCLA Medical Center, 1000 West Carson St., Box 3A, Torrance, CA 90509. E-mail: skjos{at}obgyn.humc.edu

The traditional treatment goal for gestational diabetes mellitus (GDM) has been to achieve “normal” range values for maternal glucose by diet and or insulin therapy, adapting a strategy successful in treating pregestational diabetes during pregnancy. Intensive insulin therapy to achieve strict euglycemia in GDM pregnancies has improved perinatal morbidity; however, it has not eliminated the excess rate of macrosomia compared with the reference populations (1). Increasing evidence suggests that disturbances in the intrauterine metabolic environment produced by GDM appear to increase the risk in offspring for obesity and diabetes. The obesity risk in early childhood in offspring born to mothers with GDM has been correlated with the birth weight and parental obesity, and those children who were large-for-gestational-age (LGA) at birth had obesity rates close to 40% compared with 25% in those born with normal weight (2). Studies that have attempted to reduce macrosomia rates by setting very strict glycemic targets during pregnancy have required insulin therapy in two-thirds of the women (3). However, only a minority of offspring of GDM mothers appear to be at risk for fetal overgrowth and newborn morbidity, even when GDM is untreated in blinded controlled trials (4,5). The Toronto Tri-Hospital Gestational Diabetes Project demonstrated a modest association of newborn morbidity with antenatal maternal glucose concentrations, adjusting for other risk factors (6). However, no threshold values that would suggest treatment were found.

These facts led Buchanan et al. (7) to advocate using fetal ultrasound measurements of growth in addition to maternal glycemia to identify which fetuses in utero are at increased and decreased risk for complications. This approach relaxes glycemic targets in women whose fetuses are at low risk for LGA growth and intensifies therapy by using stricter glycemic targets for those at high risk.