Comparing maternal and fetal outcomes in pregnancies associated with single versus double abnormal values in 100 gr oral glucose tolerance test (OGTT). This cohort study was performed in Arash women's Hospital, Tehran, Iran from 2019 to 2020. Patients with normal fasting blood sugar (FBS) tests were divided into two groups according to their OGTT results. The first group had a single abnormal value in their OGTT and the second group showed two abnormal values. Both groups were followed regularly until the end of pregnancy. Our results showed higher rates of macrosomia (birth of newborns weighed over 4kg) and the need for pharmacological treatment for the management of GDM in the second group (P = 0.05). There were no differences between the two groups in terms of other maternal (polyhydramnios, shoulder dystocia, operative vaginal delivery, atony, postpartum bleeding, cesarean delivery, preeclampsia, and IUFD) and fetal outcomes (Apgar score, seizure, NICU admission, and hypoglycemia in the first 24h). We found no significant differences between pregnant women with single and double abnormal values in 100 gr OGTT regarding maternal and neonatal outcomes, except for macrosomia and need for pharmaceutical treatment.