Department of Obstetrics and Gynaecology, Leicester General Hospital, University Hospitals of Leicester, Leicester, UK.
Ultrasound Obstet Gynecol. 2011 Nov;38(5):489-96. doi: 10.1002/uog.10108. Epub 2011 Oct 13.
To evaluate, by systematic review of the literature, the accuracy of first-trimester ultrasound in diagnosing early embryonic demise.
We searched MEDLINE (1951-2011), Embase (1980-2011) and the Cochrane Library (2010) for relevant citations. The reference lists of all known primary and review articles were examined. Language restrictions were not applied. Studies which evaluated the accuracy of first-trimester ultrasonography in pregnant women for the diagnosis of early embryonic demise were selected in a two-stage process and their data extracted by two reviewers. Accuracy measures including sensitivity, specificity and likelihood ratios (LRs) for abnormal and normal test results were calculated for each study and for each test threshold.
Eight primary articles with four test categories (18 2 × 2 tables), involving 872 women, evaluated the accuracy of ultrasound in diagnosing early embryonic demise. The lower limit of the 95% CI for specificity was > 0.95 in only two tests. These were an empty gestational sac with mean diameter of ≥ 25 mm and absent yolk sac with a mean gestational sac diameter of ≥ 20 mm (specificity, 1.00; 95% CI, 0.96-1.00 for both).
There is a paucity of high-quality, prospective data on which to base guidelines for the accurate diagnosis of early pregnancy demise. The findings are limited by the small number of studies and patients, the age of the studies, inclusion of symptomatic and asymptomatic women and variable reference standards for diagnosis of early pregnancy demise. Before guidelines for the safe management of threatened miscarriage can be formulated, there is an urgent need for an appropriately powered, prospective study using current ultrasound technology and an agreed reference standard for pregnancy success or loss.
通过对文献的系统回顾，评估早孕期超声在诊断早期胚胎停育中的准确性。
我们检索了 MEDLINE（1951-2011 年）、Embase（1980-2011 年）和 Cochrane 图书馆（2010 年）中相关的参考文献。检查了所有已知的原始和综述文章的参考文献列表。未应用语言限制。在两阶段过程中选择评估早孕期超声检查对诊断早期胚胎停育的准确性的研究，并由两位审阅者提取其数据。为每个研究和每个测试阈值计算了异常和正常测试结果的准确性测量值，包括敏感度、特异度和似然比（LR）。
8 篇原始文章和 4 个测试类别（18 个 2×2 表），涉及 872 名女性，评估了超声诊断早期胚胎停育的准确性。只有两项检查的特异度下限>0.95，分别是平均直径≥25mm 的空孕囊和平均孕囊直径≥20mm 的无卵黄囊（特异度，1.00；95%CI，0.96-1.00）。
缺乏高质量、前瞻性的数据来为准确诊断早期妊娠失败提供依据。这些发现受到研究和患者数量少、研究年代久远、包括有症状和无症状女性以及早期妊娠失败的诊断参考标准不同等因素的限制。在制定安全管理先兆流产的指南之前，迫切需要一项使用当前超声技术和一致的妊娠成功或失败参考标准的、适当设计的、前瞻性研究。
