Recurrence of gestational diabetes mellitus: identification of risk factors.

The objective of this paper is to evaluate the influence of maternal and neonatal factors on the recurrence of gestational diabetes mellitus (GDM). A study was conducted on 164 predominantly Hispanic patients whose index pregnancy was complicated by GDM and whose subsequent consecutive pregnancy was managed at our institution between January 1988 and December 1992. The diagnosis of GDM was based on the criteria recommended by the National Diabetes Data Group using a 100-g oral glucose tolerance test. One-hundred and eleven (68%) of the 164 women had recurrence of GDM. Fifty-three (32%) did not demonstrate recurrence in their subsequent pregnancy. Patients with recurrence had GDM diagnosed earlier (30.3 vs 32.5 weeks, p = 0.03), frequently required insulin (25 vs. 8%, p <0.05) and had more hospital admissions (32 vs. 10% p <0.05) in their index pregnancy compared to women who did not have recurrence of GDM. Women who had recurrence had elevated mean third-trimester plasma glucose values: fasting 87.6 vs. 83 mg/dL, (p = 0.009) and 2-hr postprandial 109.7 vs. 102.2 mg/dL, (p = 0.008). Neonates of patients with recurrence were heavier (3656 vs. 3373 g, p = 0.004) and had an increased incidence of macrosomia (26 vs. 10%, p <0.05). No significant differences were observed in maternal age, prepregnancy body mass index, HbgA1C values, second-trimester blood glucose levels, method of delivery, incidence of shoulder dystocia and Apgar scores between the two groups of women. Hispanic patients with history of GDM have significant risk of recurrence in their subsequent pregnancy. The risk for recurrence in women is increased if GDM is diagnosed earlier, they require insulin, have elevated third-trimester plasma glucose level, and deliver macrosomic infants in their index pregnancy. It appears that obesity does not increase the risk of recurrence of gestational diabetes in Hispanics.