What Is So Bad About a Big Baby?

The most common and significant neonatal complication clearly associated with gestational diabetes is macrosomia: an oversized baby with a birth weight greater than the 90th percentile for gestational age and sex, or a birth weight >2 SD above the normal mean birth weight. If fetal macrosomia associated with maternal diabetes is directly related to maternal glucose levels (1,2,3), then strategies to prevent hyperglycemia must be devised to treat the diabetic pregnant woman (4). However, not only is the concept that macrosomia is directly related to maternal hyperglycemia is considered controversial, but also the notion that normalizing the maternal glucose could prevent macrosomia is hotly debated. In addition, the definition of normoglycemia during pregnancy has not been adequately reported because of difficulty with measuring glucose excursions in the home setting.

The initial attempts to normalize the 24-h glucose profile were all made with hospitalized patients (5). When self-monitoring of blood glucose became available for outpatient surveillance of glucose control (6), normalization programs could be continued at home. However, the number and timing of the blood glucose determinations have not been adequately studied. In addition, reports that macrosomia occurred despite normoglycemia (7) perpetuated the philosophy that it is urgent to deliver the infant early to avoid fetal overgrowth, which was perceived to be unaffected by glycemic control. Perhaps the debate continues because many of the reports claiming that neonatal complications occur despite …