Breech for the Stars: Assessing the Use of a Physical Aid to Support Learning to

Evaluate Fetal Presentation, Position, and Situs

Background

Research Questions

Methods

Results

Discussion

Conclusion

References

Fetal ultrasound is a core tool used to help ensure the safety and health

of a woman’s pregnancy. With the fetal heartbeat being seen around six weeks’ menstrual age, ultrasound can help track the pregnancy from beginning to end. One of the most important appointments during a woman’s pregnancy is the second trimester fetal anatomy scan where the primary purpose is to evaluate for fetal abnormalities.

Fetal position and situs must be documented during this time and is essential for an accurate assessment of fetal anatomy and anomalies, but it is one of the most difficult skills for sonographers to learn. Accurate assessment of fetal presentation becomes even more important as the delivery date approaches because non-cephalic presentation has a direct impact on the delivery plan. The fetal presentation and position should be documented to ensure a safe delivery for both the mother and baby. If fetal position and situs are not recognized and documented accurately by sonographers, fetal anomalies can be missed.

This study analyzed how the introduction of a physical representation of the fetus affects the speed and accuracy of student sonographers detecting fetal presentation, position/lie, and fetal situs during an OB sonogram. This study is important because there is a gap in the literature relating the efficacy of external visual representations supporting the understanding of fetal anatomy for student sonographers.

1.) What is the impact of the use of a physical representation on the speed of student sonographer detection of fetal presentation, position, and situs during an OB sonogram? 2.) What is the impact of the use of a physical representation on the accuracy of student sonographer detection of fetal presentation, position, and situs during an OB sonogram? Hypothesis: The use of a physical representation will increase both speed and accuracy of student sonographer detection.

Nineteen student sonographers were asked to simulate longitudinal and

transverse sweeps through a fetus by mimicking scanning motions along with a cine loop to evaluate fetal position, lie, and situs.

The set up of the examination room was arranged as authentically as possible. A laptop used to show the cine loops was placed on top of the ultrasound machine in a manner that mimicked placement of the display monitor on the ultrasound machine (Figure 1). The participants mimicked actual scanning motions on a mock patient while following along with the clips. The physical aid size was authentic to that of a second or early third trimester fetus and was unclothed for better visualization of anatomical structures (Figure 2).

The cine loops were anonymized and came from previously performed exams on OB patients whose fetuses were in different positions. Participants were asked to undergo the scanning simulation and answer the questions regarding fetal position and situs at two different visits one week apart. At the first visit, participants were given the opportunity to perform a “practice” simulation with a cine loop to help orient them to the physical actions required for the simulated scan. Participants drew randomly from four possible cine loops for the scans and were randomly assigned on the first visit regarding use of the physical representation, undergoing the opposite setting on the second visit. The visits were separated by one week in order to minimize the impact of repeat learning.

Data was collected and analyzed by a statistics professional. A commonly used p-value of less than 0.1, according to the “Engineering Statistics Handbook” by Corarkin,, Tobias, and Zey12, was used as the apriori level for statistical significance.

For each of the 19 participants, answers to verbal questions regarding fetal presentation, position,

and situs, along with the time required to complete the simulated scan and answer the questions, were recorded and collated into an Excel spreadsheet for analysis. Results were analyzed to determine significance or lack thereof for the speed and accuracy of student sonographer detection during an obstetric sonogram with use of a physical representation. The use of t-scores and p-values determined the significance of the results. As mentioned in methods, a p-value of less than 0.1 (confidence greater than 90%) is considered significant and translates that results are unlikely to happen by chance. A larger t-score correlates with a smaller p-value, leading to evidence of significance.

The main finding in this research study corresponded with speed in detection. With a t-score of 1.65 and a p-value of 0.05 (95% confidence), the time taken for the participants to answer all questions determining fetal presentation, position, and situs was significantly faster in the second round. Likewise, with a t-score of 1.57 and a p-value of 0.07 (93% confidence), times were significantly faster without the physical aid in the second round.

The physical representation did not make a significant difference in the accuracy of participants’ responses. Overall accuracy in round one was 78% and in round two was 73%. When analyzing the accuracy of each question answered without the physical aid in comparison to with the physical aid, all t-scores ranged from 0.01 to 0.06 and p-values from 0.48-0.5, illustrating a lack of statistical significance.

Observing the participants in this study led to many interesting findings. Students

tend to approach learning in a variety of ways, as demonstrated when a physical representation was introduced to aid in detection of fetal presentation, position, and situs. Some students maneuvered and positioned the physical aid on top of the “mock patient”, where the patient’s stomach would be during a normal exam, while others held the physical aid in their hands the entire time and just repositioned it in front of them in-between clips. Some students needed to scan the clips through multiple times before being confident in their answers while others watched the clips once then spent more time manipulating the physical aid before answering. Others spent the majority of time putting things together in their mind before answering questions. These types of observations may help lead to a more personalized teaching style if educational programs decide to implement the introduction of physical representations in teaching detection of fetal presentation, position, and situs.

Displayed in Figure 3 as averages, along with comparing individual times in Figure 4, overall speed increased between round one and round two independent of the use of the physical aid. This suggests that the practice of determining fetal presentation, position, and situs during an obstetric sonogram can lead to quicker diagnosis. Those that used the physical representation in the first round also finished faster than those that did not use the physical representation in the first round. This increase in speed seen with the use of the physical aid in the first round supports the hypothesis that the physical representation will increase speed of detection. When analyzing times in the second round, those that did not use the physical representation were significantly faster.

Although at first look this may seem to disprove the hypothesis, the finding of the faster times in those that did not use the physical representation in the second round actually provides evidence of support. These findings suggest that repeat learning had a significant impact on the speed of detection despite the week-long interval between visits for this study. Remember, participants that did not use the physical representation in the second round had already benefited from its use in the first round and, unlike the other second round participants, did not have the extra task of using the physical aid. In Figure 5, participants that did not use the physical aid in the second round were faster in their analysis compared to those who did not use the physical aid in the first round, even if their times with the physical aid in the first round were slower than the time of those with the physical aid in the second round.

Analysis of the effect of the introduction of a physical representation on accuracy of detecting fetal presentation, position, and situs did not have the hypothesized significant impact. The change in accuracy between rounds, as well as between whether or not the physical representation was utilized, was statistically insignificant.

The results of this study provide insight into potential strategies to better support student sonographer mastery of assessment of fetal presentation, position and situs. Even though accuracy wasn’t significantly affected, time is a critical factor when student sonographers are trying to achieve clinical competency with limited scan time available during clinical rotations.

In conclusion, the data supported the hypothesis that a physical aid would increase the speed of students detecting fetal position, presentation, and situs; the null hypothesis was rejected. The data demonstrated a lack of significant impact of the physical representation on the accuracy of the students' assessment, failing to reject the null hypothesis. Participants provided accurate answers with or without the physical aid; however, they were able to do so much more quickly with its use.

Instructional strategies that support student sonographers’ ability to quickly and accurately perform essential skills can be beneficial to them during clinical rotations as well as throughout their careers.

Figure 3. Bar graph representing the average times to complete each round of the simulation and assessment with or without physical representation.

Figure 2. Physical representation used in study.Figure 1. Representation of exam room setup.

Figure 6. Bar graph representing the comparison of times to complete detection in participants who did not use the physical aid in the first round but did in the second round.

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Figure 4. Bar graph representing the comparison of participant times to complete detection between rounds one and two.

Figure 5. Graph comparing times to complete detection in participants who used the physical aid in the first round but not the second round.

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