Objectives To assess the intra‐ and interobserver reproducibility of fetal biometry measurements obtained by trainee (junior) and experienced sonographers (senior) in the contest of two training programs in obstetric ultrasound. Methods This was a prospective study on 192 women recruited ensuring an even distribution throughout gestation (18–41 weeks), at University College London Hospital (UCLH), England (87 cases), and at Maternité Regionale Universitaire de Nancy (MRUN), France (105 cases). The training took place in two training centers with experience in ultrasound training and subspecialist training in fetal medicine. Measurements for head circumference (HC), abdominal circumference (AC), and femur length (FL) were obtained twice by junior and senior sonographers, blind to their own and each other's measurements. Differences between and within sonographers were expressed in millimeters and as a percentage of fetal dimensions. Reproducibility was assessed using Bland–Altman plots. Results Reproducibility was overall high with 95% confidence intervals (CI) within <6% for intraobserver and <8% for interobserver reproducibility. Intraobserver reproducibility was lower within junior than within senior sonographers' measurements for HC (95% CI: <4% versus <3%) and FL (95% CI: <6% and < 5%). Intraobserver reproducibility was similar between the two centers/training programs (AC 95% CI: <6%). Cumulative interobserver reproducibility in both centers was similar to the reproducibility within a single site (95% CI: <5%, <8%, and <7% for HC, AC, and FL, respectively). Conclusions Reproducibility of fetal biometry measurement was high in centers with structured training programs regardless of sonographers' experience. Reproducibility was higher in sonographers who completed the training.

Results: Several themes were generated from the interviews which highlighted the difference in learning transvaginal ultrasound (TVUS) between clinical and simulation environments. The participants reported that the simulation learning environment was relaxed when compared to training during clinical practice, due to the opportunity to focus on the TV scans and to discuss the findings with colleagues in an unlimited length of time and without concerns about the patient's presence. The clinical training was reported as a stressful environment for learning due to the need to perform an invasive scan with limited experience, time constraints and limited privacy to perform learning attitudes in front of patients. Conclusions: Simulation-based training was found to be a friendly learning environment that provides a relaxed format for learning TVUS skills when compared to clinical-based training. The opportunity to train freely without time constraints in a private environment was of considerable importance to novice practitioners and was found to potentially induce efficient learning experiences once employed within the context of limited pressure. VP34.23 Usefulness of an intrapartum ultrasound simulator for midwives training: results from a RCT