Search

Introduction: Inconsistent reporting practices in third trimester ultrasound, the choice of reference charts in particular, have the potential to misdiagnose abnormal fetal growth. But this may lead to unnecessary anxiety and confusion amongst patients and clinicians and ultimately influence clinical management. Therefore, we sought to determine the extent of variability in choice of fetal biometry and Doppler reference charts and reporting practices in Australia and New Zealand., Methods: Clinicians performing and/or reporting obstetric ultrasound were invited to answer questions about fetal biometry and Doppler charts in a web-based survey., Results: At least four population-based charts are in current use. The majority of respondents (78%) report the percentile for known gestational age (GA) alongside measurements and 63% using a cut-off of estimated fetal weight (EFW) < 10 th percentile when reporting small for gestational age (SGA) and/or fetal growth restriction (FGR). The thresholds for the use of fetal and maternal Doppler in third trimester ultrasound varied in terms of the GA, EFW cut-off, and how measures were reported. The majority of respondents were not sure of which Doppler charts were used in their practice., Conclusion: This survey revealed inconsistencies in choice of reference chart and reporting practices. The potential for misdiagnosis of abnormal fetal growth remains a significant issue., Competing Interests: Debra Paoletti is a member of the ASUM board of directors, the ASUM DMU board of examiners and an associate editor of AJUM., (© 2021 Australasian Society for Ultrasound in Medicine.)

Objective: To report on the findings of a survey of sonographer skill-teaching practices in Australia using the SonoSTePs tool., Method: A cross-sectional survey of all qualified sonographers registered with the Australian Sonographer Accreditation Registry., Results: The 528 responses showed the use of a two-step skill-teaching approach to teach scanning skills and the incorporation of additional instructional practices to support a learner's initial acquisition of scanning skills, which include: providing coaching and guidance as the skill is practised; performing physical guidance; providing immediate error correction; and providing end-task feedback. Based on our findings, sonographer skill-teaching practices fall short of best pedagogical approaches., Conclusion: There is a pressing need to identify the optimal pedagogical approaches to teach complex psychomotor scanning skills. Research is required to ensure that the scanning skills are taught efficiently and that the pedagogical approaches to teach scanning skills foster the learner's long-term retention of the skill. There is also an accompanying need for sonographers involved in teaching scanning skills to have knowledge of the motor-learning theories and principles related to teaching a complex psychomotor skill., Competing Interests: No disclosure., (© 2020 Australasian Society for Ultrasound in Medicine.)

Objective: To report the qualitative findings of the inaugural survey of sonographer skill-teaching practices in Australia using the SonoSTePs tool., Method: A national cross-sectional survey of all qualified sonographers registered with the Australian Sonographer Accreditation Registry. A mix of quantitative and qualitative data was collected. This paper reports on a content analysis of the qualitative data relating to factors that impact on teaching., Results: A total of 528 respondents provided a range of qualitative data in five extended text questions. Five key themes emerged from the analysis: limited protected teaching time; perceived skill complexity; learner skill level and credentials; avoiding overwhelming the learner; and patient well-being and their willingness to be scanned. Novel teaching interactions between the educator and the student sonographer were identified. Information was provided to learners at four time-points across the continuum of clinical practice performance. The type, quantity and purpose of the information provided by the educator to the learner differed at each of these four time-points and included the following: (i) pre-task clarification, guidance and practice norms; (ii) in-task verbal information and scanning support; (iii) post-task support and information; and (iv) end-task or terminal feedback., Conclusion: This is the first published study which reports the push and pull factors affecting pedagogical approaches to teach and learn complex scanning skills. These results provide a corpus of new knowledge, and the first analysis and review, about the pedagogical findings related to teaching scanning skills for clinical practice. This study provides a basis for further research and practice improvements., Competing Interests: No disclosure., (© 2020 Australasian Society for Ultrasound in Medicine.)

The placenta is the link between mother and fetus and its function is central to a successful pregnancy. The predominant theory within the literature is that the development of placental dysfunction is a result of abnormal trophoblast invasion early in pregnancy. Knowledge of the development of the early placenta and the establishment of the fetomaternal circulation assists in understanding the origins of placental dysfunction which manifest later in pregnancy. Perinatally, chronic placental dysfunction may result in a growth-restricted fetus, maternal problems such as gestational hypertension, pre-eclampsia, eclampsia and pregnancy complications such as placental abruption, preterm labour and delivery. In addition, the growth-restricted fetus and the mother are at an increased risk of a myriad of disorders later in life. The role of ultrasound in the assessment of first trimester pregnancy is evolving with the potential for value in the prediction of placental function in later pregnancy. This review will address two aims, first to describe the development of the placenta from fertilisation to 12 weeks' gestation, correlating this with first trimester ultrasound findings. Second, to describe the link between placental development and function later in pregnancy. Understanding the link between early placental development and later placental function is essential in directing the focus of new research addressing the role of ultrasound in the first trimester in the prediction of adverse obstetric outcomes., (© 2017 Australasian Society for Ultrasound in Medicine.)

We aimed to compare the value of transabdominal (TA) and transvaginal (TV) approaches for assessing the risk of a low-lying placenta. This involved a comparison of TA and TV measurements between the leading placental edge and the internal cervical os. We also assessed the intra-/interobserver variation for these measurements and the efficacy of TA measures in screening for a low placenta., Methodology: Transabdominal and TV measurements of the leading placental edge to the internal cervical os were performed on 369 consecutive pregnancies of 16-41 weeks' gestation. The difference (TA-TV) from the mean was calculated and plotted against gestational age. Bland-Altman plots and paired t-tests were used to look at the differences in TA/TV measurement. Screening performance of a transabdominal approach was compared to a transvaginal 'gold standard'. Nonparametric methods were used to calculate the area under the receiver operator characteristics (ROC) curve. Intra-/interobserver variations were also calculated., Results: Of the pregnancies, 278 had a leading placental edge that was visible with the TV approach. Differences (TA-TV) ranged from -50 mm to +57 mm. Bland-Altman plot shows that TA measurements overestimated the distance compared with the TV measurements; the average difference in measurement was 12.0 mm (95% confidence interval 9.9-14.1). The sensitivity, specificity and negative predictive values of a TA approach were 18.2%, 97.5% and 87.2%, respectively. The receiver operator characteristics area between gestational weeks 16-23 was 0.81 (95% CI: 0.76-0.86)., Conclusion: The TA approach has a low sensitivity for detecting a low-lying placenta as choosing a TA cut-off with sensitivity >90% will decrease the specificity to 50%., (© 2017 Australasian Society for Ultrasound in Medicine.)

Objective: To report on the initial content development of the sonographer skill teaching practices survey (SonoSTePs) tool to measure skill teaching perceptions., Method: The nine-step model by Sarantakos [ Social Research , 3rd edn. London: Palgrave Macmillan; 2005. 1-464], was used to guide the initial development of the instrument, content domains, and the generated questions. The face and content validity of the instrument was established after progressing through two expert panel reviews (experts in the fields of education, statistics, and ultrasound) and two pilot tests., Results: Results of the pilot testing identified differing discriminant variability (variation ratios) between the use of a five-point and a seven-point Likert-type frequency scale. In particular, the pilot two (P2) 30-item instrument, using a frequency seven-point Likert-type scale, resulted in good variation ratios (0.68 across 24 items; SD=0.11), demonstrating discriminatory ability between individual participant's teaching practices., Conclusions: The content and face validity of the SonoSTePs instrument has been established using principles of questionnaire construction and development., (© 2016 Australasian Society for Ultrasound in Medicine.)

Objective: To develop reference ranges for the ductus venosus (DV) and tricuspid valve (TV) waveforms at 11-14 weeks and define auditable standards to assess operator measurement performance., Materials and Methods: A single operator prospectively obtained quantitative measurements of a number of DV and TV Doppler indices to develop medians and 90% reference intervals (RIs). Measurement agreement studies between two experienced operators were also performed. The measurement bias of three additional operators was subsequently assessed using the newly defined auditable standards., Results: Doppler measurements were obtained in 292 patients (DV) and 321 patients (TV). Reference ranges were constructed for DV pulsatility index for veins (PIV) which did not change over gestation (mean 1.06; 90% RI 0.86-1.23) and for the TV E-A ratio reference range which was positively correlated with gestation. Measurement agreement studies on 30 additional patients showed the within-operator agreement was almost perfect for DV PIV (ICC, intraclass correlation 0.82-0.86) and strong for TV E-A ratio (ICC 0.68-0.78) while the between-operator agreement was good for both DV PIV and TV E-A ratio measurements (ICC 0.46 for both)., Discussion: Development of local reference ranges enabled the definition of quantitative auditable standards that can be utilised in assessment of operator training and ongoing Doppler measurement quality assurance. Measurements of DV PIV and TV E-A ratio by experienced operators were found to be reproducible., (© 2016 Australasian Society for Ultrasound in Medicine.)

Objective : To compare transabdominal (TA) and transvaginal (TV) ultrasound assessment of cervical length at 16-41 weeks gestation. Methods : TA and TV ultrasound measurements of cervical length were made on 491 pregnancies of 16-41 weeks gestation. Cervical length was measured from internal to external cervical os. Bland-Altman plots and Wilcoxon signed rank test were used to evaluate differences between TA and TV measurements. Results : The validity of the TA method depended on cervical length. Although the TA method underestimated cervical length by 2.0 mm on average ( P < 0.001), Bland Altman plots showed an inverse trend with shorter cervixes. In women with a cervix < 25 mm (n = 30) based on TV scan measurement, TA overestimated cervical length by 12 mm (P < 0.001). The sensitivity and specificity of TA as a test to detect cervical length < 25 mm were 10% (95% CI: 2.1-26%) and 94% (95% CI: 92-96%) respectively; the negative LR was 0.96 (95% CI: 0.84-1.08). The maximum area under the ROC curve would be obtained at a TA cut-off = 32 mm (to detect a cervix < 25 mm), corresponding to a sensitivity of 77% and a specificity of 58%. Conclusion : TA measurements do not reflect TV assessment accurately, particularly if the cervix is short. At 24-34 weeks, a policy of proceeding to TV scan if TA measurement is < 25 mm will only detect 10% of affected pregnancies and has a poor positive predictive value so is of limited value as a predictive tool for women attending with symptoms and signs of preterm labour > 24 weeks gestation. There is no value in TA assessment of the cervix > 36 weeks.