Toscano Marika, Marini Thomas, Lennon Clare, Erlick Mariah, Silva Hannah, Crofton Kathryn, Serratelli William, Rana Neel, Dozier Ann M, Castaneda Benjamin, Baran Timothy M, Drennan Kathryn
Division of Maternal-Fetal Medicine, Department of Gynecology & Obstetrics, Johns Hopkins University School of Medicine, Baltimore, Maryland; the Department of Imaging Sciences, the Department of Public Health Sciences, and the Department of Obstetrics & Gynecology, University of Rochester Medical Center, and the University of Rochester School of Medicine and Dentistry, Rochester, New York; and the Division of Electric Engineering, Department of Academic Engineering, Pontificia Universidad Catolica del Peru, Lima, Peru.
Obstet Gynecol. 2023 May 1;141(5):937-948. doi: 10.1097/AOG.0000000000005139. Epub 2023 Apr 5.
To estimate the diagnostic accuracy of blind ultrasound sweeps performed with a low-cost, portable ultrasound system by individuals with no prior formal ultrasound training to diagnose common pregnancy complications.
This is a single-center, prospective cohort study conducted from October 2020 to January 2022 among people with second- and third-trimester pregnancies. Nonspecialists with no prior formal ultrasound training underwent a brief training on a simple eight-step approach to performing a limited obstetric ultrasound examination that uses blind sweeps of a portable ultrasound probe based on external body landmarks. The sweeps were interpreted by five blinded maternal-fetal medicine subspecialists. Sensitivity, specificity, and positive and negative predictive values for blinded ultrasound sweep identification of pregnancy complications (fetal malpresentation, multiple gestations, placenta previa, and abnormal amniotic fluid volume) were compared with a reference standard ultrasonogram as the primary analysis. Kappa for agreement was also assessed.
Trainees performed 194 blinded ultrasound examinations on 168 unique pregnant people (248 fetuses) at a mean of 28±5.85 weeks of gestation for a total of 1,552 blinded sweep cine clips. There were 49 ultrasonograms with normal results (control group) and 145 ultrasonograms with abnormal results with known pregnancy complications. In this cohort, the sensitivity for detecting a prespecified pregnancy complication was 91.7% (95% CI 87.2-96.2%) overall, with the highest detection rate for multiple gestations (100%, 95% CI 100-100%) and noncephalic presentation (91.8%, 95% CI 86.4-97.3%). There was high negative predictive value for placenta previa (96.1%, 95% CI 93.5-98.8%) and abnormal amniotic fluid volume (89.5%, 95% CI 85.3-93.6%). There was also substantial to perfect mean agreement for these same outcomes (range 87-99.6% agreement, Cohen κ range 0.59-0.91, P<.001 for all).
Blind ultrasound sweeps of the gravid abdomen guided by an eight-step protocol using only external anatomic landmarks and performed by previously untrained operators with a low-cost, portable, battery-powered device had excellent sensitivity and specificity for high-risk pregnancy complications such as malpresentation, placenta previa, multiple gestations, and abnormal amniotic fluid volume, similar to results of a diagnostic ultrasound examination using a trained ultrasonographer and standard-of-care ultrasound machine. This approach has the potential to improve access to obstetric ultrasonography globally.
评估由未接受过正规超声培训的人员使用低成本便携式超声系统进行盲法超声扫描以诊断常见妊娠并发症的诊断准确性。
这是一项单中心前瞻性队列研究，于2020年10月至2022年1月在孕中期和孕晚期的人群中进行。未接受过正规超声培训的非专业人员接受了关于一种简单的八步方法的简短培训，该方法用于进行有限的产科超声检查，即基于体外体表标志使用便携式超声探头进行盲扫。扫描结果由五名不知情的母胎医学亚专科医生解读。将盲法超声扫描识别妊娠并发症（胎位异常、多胎妊娠、前置胎盘和羊水过少）的敏感性、特异性、阳性预测值和阴性预测值与作为主要分析的参考标准超声检查结果进行比较。还评估了一致性的kappa值。
培训人员对168名不同的孕妇（248例胎儿）进行了194次盲法超声检查，平均孕周为28±5.85周，共获得1552段盲扫电影剪辑。有49份超声检查结果正常（对照组），145份超声检查结果异常且已知存在妊娠并发症。在该队列中，总体上检测预定妊娠并发症的敏感性为91.7%（95%CI 87.2-96.2%），多胎妊娠（100%，95%CI 100-100%）和非头位（91.8%，95%CI 86.4-97.3%）的检测率最高。前置胎盘（96.1%，95%CI 93.5-98.8%）和羊水过少（89.5%，95%CI 85.3-93.6%）的阴性预测值较高。对于这些相同的结果，也存在高度至完美的平均一致性（一致性范围为87-99.6%，Cohen κ范围为0.59-0.91，所有P<0.001）。
仅使用体外解剖标志并按照八步方案进行指导，由未经培训的操作人员使用低成本、便携式、电池供电设备对孕妇腹部进行盲法超声扫描，对于胎位异常、前置胎盘、多胎妊娠和羊水过少等高风险妊娠并发症具有出色的敏感性和特异性，类似于使用经过培训的超声检查人员和标准护理超声设备进行诊断性超声检查的结果。这种方法有可能在全球范围内改善产科超声检查的可及性。
