The purpose of this prospective, nonconcurrent study was to determine whether maternal hypoglycemia, as measured by a 3-hour glucose tolerance test, is associated with pregnancies resulting in growth-retarded infants. Our results demonstrate that maternal hypoglycemia is significantly associated with intrauterine growth retardation other than the low birth weight type and that the 3-hour glucose tolerance test is an effective early screening test in detecting pregnancies at risk of fetal growth retardation.