Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD.
Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD; Howard University Hospital, Washington, DC.
Am J Obstet Gynecol. 2020 Aug;223(2):242.e1-242.e22. doi: 10.1016/j.ajog.2020.02.025. Epub 2020 Feb 25.
Pregnancy loss prediction based on routinely measured ultrasound characteristics is generally aimed toward distinguishing nonviability. Physicians also use ultrasound indicators for patient counseling, and in some cases to decide upon the frequency of follow-up sonograms. To improve clinical utility, allocation of cut-points should be based on clinical data for multiple sonographic characteristics, be specific to gestational week, and be determined by methods that optimize prediction.
To identify routinely measured features of the early first trimester ultrasound and the gestational age-specific cut-points that are most predictive of pregnancy loss.
This was a secondary analysis of 617 pregnant women enrolled in the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial; all women had 1-2 previous pregnancy losses and no documented infertility. Each participant had a single ultrasound with a detectable fetal heartbeat between 6 weeks 0 days and 8 weeks 6 days. Cut-points for low fetal heart rate and small crown-rump length were separately defined for gestational weeks 6, 7, and 8 to optimize prediction. Identity and log-binomial regression models were used to estimate absolute and relative risks, respectively, and 95% confidence intervals between jointly categorized low fetal heart rate, small crown-rump length, and clinical pregnancy loss. Adjusted models accounted for gestational age at ultrasound in weeks. Missing data were addressed using multiple imputation.
A total of 64 women experienced a clinical pregnancy loss following the first ultrasound (10.4%), 7 were lost to follow-up (1.1%), and 546 women (88.5%) had a live birth. Low fetal heart rate and small crown-rump length (≤122, 123, and 158 bpm; ≤6.0, 8.5, and 10.9 mm for gestational weeks 6, 7, and 8, respectively) were independent predictors of clinical pregnancy loss, with greatest risks observed for pregnancies having both characteristics (relative risk, 2.08; 95% confidence interval, 1.24-2.91). The combination of low fetal heart rate and small crown-rump length was linked to a 16% (95% confidence interval, 9.1-23%) adjusted absolute increase in risk of subsequent loss, from 5.0% (95% confidence interval, 1.5-8.5%) to 21% (95% confidence interval, 15-27%). Abnormal yolk sac diameter or the presence of a subchorionic hemmhorage did not improve prediction of clinical pregnancy loss.
Identified cut-points can be used by physicians for patient counseling, and in some cases to decide upon the frequency of follow-up sonograms. The specified criteria should not be used to diagnose nonviability.
基于常规测量的超声特征预测妊娠丢失，通常旨在区分无生机。医生还使用超声指标为患者提供咨询，并在某些情况下决定后续超声检查的频率。为了提高临床实用性，应根据多个超声特征的临床数据、针对特定孕周以及通过优化预测的方法来分配切点。
确定早孕期超声的常规测量特征和与妊娠丢失最相关的特定孕周切点。
这是 Effects of Aspirin in Gestation and Reproduction (EAGeR) 试验中 617 名孕妇的二次分析；所有女性均有 1-2 次既往妊娠丢失，且无明确的不孕病史。每位参与者在 6 周 0 天至 8 周 6 天期间均进行了一次可检测到胎儿心跳的超声检查。分别为 6、7 和 8 孕周定义低胎儿心率和小头臀长的切点，以优化预测。使用身份和对数二项式回归模型分别估计绝对风险和相对风险，以及共同分类的低胎儿心率、小头臀长和临床妊娠丢失之间的 95%置信区间。调整模型考虑了超声检查时的孕周。使用多重插补处理缺失数据。
共有 64 名女性在首次超声检查后经历了临床妊娠丢失（10.4%），7 名女性失访（1.1%），546 名女性（88.5%）分娩。低胎儿心率和小头臀长（≤122、123 和 158 bpm；6、7 和 8 孕周时分别为≤6.0、8.5 和 10.9 mm）是临床妊娠丢失的独立预测因素，同时存在这两种特征的妊娠风险最大（相对风险，2.08；95%置信区间，1.24-2.91）。低胎儿心率和小头臀长的组合与后续丢失风险增加 16%（95%置信区间，9.1-23%）相关，从 5.0%（95%置信区间，1.5-8.5%）调整为 21%（95%置信区间，15-27%）。异常卵黄囊直径或存在绒毛膜下血肿并不能提高临床妊娠丢失的预测。
确定的切点可由医生用于患者咨询，并在某些情况下决定后续超声检查的频率。指定的标准不应用于诊断无生机。
