Objectives There is a controversy about which growth chart is more suitable for the identification SGA worldwide. We evaluated the performance of the INTERGROTWH 21st and WHO fetal growth charts for the identification of SGA in a large cohort of deliveries from five centres across three countries in Latin America. Methods Prospectively gathered maternity data of all women who gave birth between 24 ‐ 42 weeks across three countries (Colombia, Peru, Mexico) during 2017–2018 (n = 32,318 singleton births). Infants were classified as AGA or SGA (birthweight<10th centile) according to IG21 and WHO standards. Next, we compared among the groups of SGA cases identified by each and both standards, the rate of low Apgar score, ponderal and cephalization indexes. Results The rate of SGA detected by WHO was significantly higher than that detected by IG21 [12.6% (4089/32318) vs. 5% (1619/32318); p < 0.001]. There was an disagreement in the identification of SGA by each growth standard: 2545 (7.87%) SGA cases were identified only by WHO, while 75 (0.23%) SGA cases were identified only by IG21. The rate of low APGAR score at 5min was significantly higher in SGA cases identified only by WHO compared to those AGA [1.03% vs. 0.61%; p < 0.001). In SGA cases identified only by WHO ponderal and cephalisation indexes were also significantly lower in those cases compared to AGA, suggesting features of intrauterine undernutrition in those cases that were assigned as AGA by IG21. Conclusions In a large population from Latin America, the WHO standard seems to be able to identify significantly more cases of SGA newborns compared to IG21 and those newborns had a similar pattern of intrauterine malnutrition than the cases of SGA identified by both curves.