GESTATIONAL DIABETES - DOES THE PRESENCE OF RISK-FACTORS INFLUENCE PERINATAL OUTCOME

OBJECTIVE: Our purpose was to determine whether gestational diabetics with risk factors for gestational diabetes have worse glucose toleranc e and poorer birth outcomes than those without risk factors. STUDY DES IGN: We conducted a nonconcurrent cohort study of gestational diabetic s identified by universal screening and delivered from Jan, 1, 1990, t o Dec. 31, 1992. Multiple gestations and patients with chronic medical conditions were excluded. The following risk factors for gestational diabetes mellitus were abstracted: obesity (> 80 kg), family history o f diabetes, previous gestational diabetes mellitus, and previous macro somic, stillborn, or anomalous fetus. Patients with one or more risk f actors were compared with those without risk factors. A group of low-r isk nondiabetic patients served as controls. The incidences of A(2) di abetes mellitus, cesarean section, neonatal macrosomia, and shoulder d ystocia were the outcome variables of interest. RESULTS: Selective scr eening would have failed to detect 43% of gestational diabetics. Twent y-eight percent of the missed gestational diabetics would have require d insulin (class A(2)). When compared with controls, patients with ges tational diabetes mellitus were at increased risk for macrosomia (26% vs 11%, p < 0.01), cesarean section (37% vs 15%, p < 0.01), and should er dystocia (9% vs 2%, p < 0.05). Patients with and without risk facto rs did not differ in mean maternal age, gestational age at delivery, b irth weight, incidence of requiring insulin, macrosomia, or cesarean d elivery. The similarities between those with and without risk factors remained after stratification by maternal age (greater than or equal t o 30 years). CONCLUSION: Gestational diabetics are at increased risk f or adverse birth outcomes compared with low-risk controls. Class A(2) diabetes mellitus and fetal macrosomia with its attendant risks are eq ually prevalent among patients with and without risk factors for gesta tional diabetes mellitus. Because > 40% of cases will be missed with s elective screening, universal screening should be favored for detectio n of gestational diabetes mellitus.