Objective - This study aims to assess fetal physiology training in terms of theoretical knowledge, fetal heart rate interpretation and use of second-line examination. Design - - Single-center prospective study (CHU Lille, France) Setting - The evaluation of fetal well-being during labor is based on fetal heart rate (FHR) analysis and requires knowledge of physiology. Population - Obstetrics and gynecology residents from November 2017 to November 2018 (n=34) Methods – The training was conducted in 3 steps: a session of FHR interpretation and the use of fetal scalp blood sampling (FBS) on clinical cases, then a teaching session on fetal physiology, and finally another session on the same cases presented in the first one. Main Outcome Measures – Theoretical knowledge evaluation (MCQs), number of FBS requested, the reproducibility of responses. Results - Almost 3% estimated their training sufficient on fetal physiology, 11.8% on fetal heart rate analysis and 14.7% on second-line examination. The training allowed a significant improvement of their theoretical knowledge evaluation (mediane [IQR] : 1.5[1.0 to 2.0] vs 4.0[3.0 to 4.5] of MCQs, p <0.001)), a decrease in the number of FBS requested (36.3% vs 29.5%, p =0.002). The Krippendorff’s alpha index assessing the reproducibility of their response was significantly improved, reflecting a better homogenization of practices (alpha [IC95] : 0.60[0.55 to 0.65] vs 0.72[0.67 to 0.76]). Conclusions - The improvement of knowledge in fetal physiology allows a better interpretation of the FHR with better indications of second-line examinations and a homogenization of practices. Funding- None