Objective: To compare the feasibility of performing a complete first trimester fetal anatomy screening between two operators with different levels of experience using the protocol of the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), and to compare the duration of scan and learning curve of each operator as secondary outcomes.
Methods: A prospective study was conducted on singleton pregnancies at 11+0-13+6 weeks of gestation. Transabdominal ultrasound anatomy screening was performed by a maternal fetal medicine (MFM) staff (operator 1) or a first year MFM fellow (operator 2) following ISUOG guidelines. The visibility of fetal structures and time taken by each operator were recorded and analyzed.
Results: Data from 98 participants in operator 1 group and 96 participants in operator 2 group were analyzed. The success rate of visualizing all structures was feasible in 87.8% and 91.7% (p = .370) of cases in operator 1 and operator 2, respectively. The significant improvement in visualization success rate was observed between the first 50 and the last 50 scans in both groups (p = .004 vs. p = .006). Average time spent on the exam by operator 1 was significantly shorter than the time spent by operator 2 (11.3 ± 4.8 min vs. 15.0 ± 6.2 min; p < .001).
Conclusion: Completeness of first trimester fetal anatomy screening following ISUOG protocol were feasible with no statistical difference between the two different levels of experienced operators. Moreover, time allocatable with a brief learning curve were demonstrated in both groups.
Keywords: First trimester screening; ISUOG protocol; feasibility; learning curve.