Child growth is one of the important health indicators in pediatric care. Few studies focused on the impact of prenatal exposure to gestational diabetes mellitus (GDM) on growth trajectories particular in early years of childhood. The aim of this study was identifying growth pattern of GDM exposed offspring's, comparison with new WHO child growth standards.In a population-based Longitudinal study 438 infants exposed to gestational diabetes in utero, aged 0-24 months, born between 2014 and 2016 with at least 9 visits in first 2 years of life were enrolled. Twenty health centers of Ahvaz city (Capital of Khuzestan province, located in south western of Iran) and two referral centers for neonatal hypothyroidism involved the study.Of 438 GDM exposed infants, 54.6% were boys. Incidence of low birth weight and macrosomia were 4.6% and 8.7% respectively.4.6% had birth weight less than 2500gr and 8.7% was rate of macrosomia. Boys had higher weight and BMI than girls. Peak of BMI was 17.8 (±2.07) at 6 months after Gender was significant factor in predicted of BMI growth trajectories in GDM exposed children (p = 0.001). BMI in GDM exposed infants, in first 2 years of life was higher than WHO growth standards 2006 (P < 0.01).Medians of BMI in GDM exposed infants in all measures was higher than WHO reference data 2006 (P < 0.01). Obesity prevention programs must be priority in GDM exposed infants.