Perinatal Outcomes in Mexican Women with Untreated Mild Gestational Diabetes Mellitus Diagnosed by the International Association of Diabetes and Pregnancy Study Groups Criteria

PURPOSE: To compare the risk of adverse perinatal outcomes (APO) between pregnant women with mild gestational diabetes mellitus (GDM) diagnosed by the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria, on no specific treatment, versus pregnant women without GDM. PATIENTS AND METHODS: A retrospective cohort study of pregnant women referred to the Instituto Nacional de Perinatología, in Mexico City, for prenatal care and delivery. Eligibility criteria were singleton pregnancy, age >18 years, gestational age 20–28 weeks, and no history of pre-gestational diabetes. The study population was divided into two groups: Group 1, comprising women with mild GDM defined by one abnormal glucose value at the oral glucose tolerance test (OGTT) according to IADPSG criteria [fasting: 5.1–5.2 mmol/L (92–94 mg/dL) or 2h 8.5–8.56 mmol/L (153–154 mg/dL)], who did not receive specific treatment for GDM, and Group 2, comprising women without GDM, matched for maternal age and pre-gestational body mass index (BMI). Women with two or more abnormal OGTT values, pre-gestational diabetes, any chronic disease, or multiple pregnancies were excluded. RESULTS: As many as 282 women were included in each group. There were no significant differences in basal characteristics between groups. APO analysis showed that newborn weight was significantly higher in Group 1 (3042.4±499g) vs Group 2 (2910±565g) p=0.003; conversely, the incidence of large for gestational age (LGA) and macrosomic neonates was similar in both groups (6 vs 5.7% and 2.1 vs 2.2%, respectively). There were no differences in rates of preeclampsia and gestational hypertension, cesarean and preterm delivery, or premature rupture of membranes. A sub-analysis by maternal pre-gestational BMI showed that LGA incidence was significantly higher among babies born to women with pre-gestational BMI ≥30 kg/m(2) in both groups. CONCLUSION: The risk of APO was similar among Mexican women with mild untreated GDM diagnosed by IADPSG criteria, compared to pregnant women without GDM. Pre-gestational BMI was an independent risk factor for LGA.