Abstract：
BACKGROUND: Vaginal bleeding in the first trimester of pregnancy generates anxiety and uncertainty for expecting parents. The ability to determine pregnancy outcome through a first trimester ultrasound scan remains a challenge in obstetrics. Several first trimester ultrasound markers used individually or in combination, as well as ultrasound markers used in combination with biochemical markers, have been studied to determine their predictive value in pregnancy outcome. This scoping review was performed to determine which markers have already been investigated for this purpose.
METHODS: An extensive and systematic database search was performed using four different categories of keywords which were combined using Boolean terms. A total of 14 variables were included on the final data charting forms. Data was synthesised collectively for each variable and then separately for the studies analysing only one marker. For the studies which analysed multiple markers, data was synthesised based on the number of markers per study.
RESULTS: The search yielded 3608 studies, of which 128 were ultimately used for this review. Data extraction, based on predetermined eligibility criteria, was performed by two authors independently. Seventy-seven (62.6%) studies investigated the predictive value of a single ultrasound marker. The remaining 46 (37.4%) studies explored multiple markers, of which at least one was an ultrasound marker.
CONCLUSIONS: This review identified several discrepancies among different studies. This highlights the need for better consensus among researchers to allow for the design of a predictive model which enables extrapolation of findings to all pregnant women.
CONCLUSIONS: Through the study of ultrasound and biochemical markers in the first trimester of pregnancy, clinicians may provide a more accurate prediction of pregnancy outcome following threatened miscarriage.
METHODS: An extensive and systematic database search was performed using four different categories of keywords which were combined using Boolean terms. A total of 14 variables were included on the final data charting forms. Data was synthesised collectively for each variable and then separately for the studies analysing only one marker. For the studies which analysed multiple markers, data was synthesised based on the number of markers per study.
RESULTS: The search yielded 3608 studies, of which 128 were ultimately used for this review. Data extraction, based on predetermined eligibility criteria, was performed by two authors independently. Seventy-seven (62.6%) studies investigated the predictive value of a single ultrasound marker. The remaining 46 (37.4%) studies explored multiple markers, of which at least one was an ultrasound marker.
CONCLUSIONS: This review identified several discrepancies among different studies. This highlights the need for better consensus among researchers to allow for the design of a predictive model which enables extrapolation of findings to all pregnant women.
CONCLUSIONS: Through the study of ultrasound and biochemical markers in the first trimester of pregnancy, clinicians may provide a more accurate prediction of pregnancy outcome following threatened miscarriage.
摘要：
背景：妊娠早期阴道出血会给父母带来焦虑和不确定感。通过妊娠早期超声扫描确定妊娠结局的能力仍然是产科的挑战。几个早期妊娠超声标记物单独或组合使用，以及与生化标志物结合使用的超声标志物，已被研究以确定其对妊娠结局的预测价值。进行此范围审查以确定已经为此目的研究了哪些标记。
方法：使用四种不同类别的关键字进行了广泛而系统的数据库搜索，这些关键字使用布尔术语进行组合。最终数据图表表格中包含了总共14个变量。针对每个变量共同合成数据,然后针对仅分析一个标记的研究分别合成数据。对于分析多个标记的研究，数据是根据每个研究的标记数量合成的。
结果：搜索产生了3608项研究，其中128人最终用于本次审查。数据提取,根据预定的资格标准，由两名作者独立完成。77项（62.6％）研究调查了单个超声标记的预测价值。其余46项(37.4%)研究探索了多种标志物，其中至少一个是超声标记。
结论：这篇综述发现了不同研究之间的一些差异。这凸显了需要在研究人员之间达成更好的共识，以便设计一个预测模型，该模型能够将研究结果外推到所有孕妇。
结论：通过对妊娠早期超声和生化指标的研究，临床医生可以更准确地预测先兆流产后的妊娠结局.
方法：使用四种不同类别的关键字进行了广泛而系统的数据库搜索，这些关键字使用布尔术语进行组合。最终数据图表表格中包含了总共14个变量。针对每个变量共同合成数据,然后针对仅分析一个标记的研究分别合成数据。对于分析多个标记的研究，数据是根据每个研究的标记数量合成的。
结果：搜索产生了3608项研究，其中128人最终用于本次审查。数据提取,根据预定的资格标准，由两名作者独立完成。77项（62.6％）研究调查了单个超声标记的预测价值。其余46项(37.4%)研究探索了多种标志物，其中至少一个是超声标记。
结论：这篇综述发现了不同研究之间的一些差异。这凸显了需要在研究人员之间达成更好的共识，以便设计一个预测模型，该模型能够将研究结果外推到所有孕妇。
结论：通过对妊娠早期超声和生化指标的研究，临床医生可以更准确地预测先兆流产后的妊娠结局.
