A systematic search was performed to identify relevant studies published until June 2022, using the databases PubMed, Web of Science, and Scopus.
Cohort studies in low-risk or unselected singleton pregnancies with screening ultrasound performed at ≥32 weeks of gestation were used.
The estimated fetal weight and abdominal circumference were assessed as index tests for the prediction of small for gestational age (birthweight of <10th percentile) and detecting fetal growth restriction (estimated fetal weight of <10th percentile and/or abdominal circumference of <10th percentile). The quality of the included studies was independently assessed by 2 reviewers using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. For the meta-analysis, hierarchical summary area under the receiver operating characteristic curves were constructed, and quantitative data synthesis was performed using random-effects models.
The analysis included 25 studies encompassing 73,981 low-risk pregnancies undergoing third-trimester ultrasound assessment for growth, of which 5380 neonates (7.3%) were small for gestational age at birth. The pooled sensitivities for estimated fetal weight of <10th percentile and abdominal circumference of <10th percentile in predicting small for gestational age were 36% (95% confidence interval, 27%-46%) and 37% (95% confidence interval, 19%-60%), respectively, at 32 weeks ultrasound and 48% (95% confidence interval, 41%-56%) and 50% (95% confidence interval, 25%-74%), respectively, at 36 weeks ultrasound. The pooled specificities for estimated fetal weight of <10th percentile and abdominal circumference of <10th percentile in detecting small for gestational age were 93% (95% confidence interval, 91%-95%) and 95% (95% confidence interval, 85%-98%), respectively, at 32 weeks ultrasound and 93% (95% confidence interval, 91%-95%) and 97% (95% confidence interval, 85%-98%), respectively, at 36 weeks ultrasound. The observed diagnostic odds ratios for an estimated fetal weight of <10th percentile and an abdominal circumference of <10th percentile in detecting small for gestational age were 8.8 (95% confidence interval, 5.4-14.4) and 11.6 (95% confidence interval, 6.2-21.6), respectively, at 32 weeks ultrasound and 13.3 (95% confidence interval, 10.4-16.9) and 36.0 (95% confidence interval, 4.9-260.0), respectively, at 36 weeks ultrasound. The pooled sensitivity, specificity, and diagnostic odds ratio in predicting fetal growth restriction were 71% (95% confidence interval, 52%-85%), 90% (95% confidence interval, 79%-95%), and 25.8 (95% confidence interval, 14.5-45.8), respectively, at 32 weeks ultrasound and 48% (95% confidence interval, 41%-55%), 94% (95% confidence interval, 93%-96%), and 16.9 (95% confidence interval, 10.8-26.6), respectively, at 36 weeks ultrasound. Abdominal circumference of <10th percentile seemed to have comparable sensitivity to estimated fetal weight of <10th percentile in predicting small-for-gestational-age neonates.
An ultrasound assessment of the fetal biometry at 36 weeks of gestation seemed to have better predictive accuracy for small-for-gestational-age neonates than an ultrasound assessment at 32 weeks of gestation. However, an opposite trend was noted when the outcome was fetal growth restriction. Fetal abdominal circumference had a similar predictive accuracy to that of estimated fetal weight in detecting small-for-gestational-age neonates.
方法:使用数据库PubMed进行了系统搜索,以确定直到2022年6月发表的相关研究,WebofScience,还有Scopus.
方法:对低风险或未选择的单胎妊娠进行队列研究,并在妊娠≥32周时进行超声筛查。
方法:评估胎儿体重和腹围作为预测胎龄小(出生体重<10百分位数)和检测胎儿生长受限(估计胎儿体重<10百分位数和/或腹围<10百分位数)的指标测试。纳入研究的质量由2名评审员使用诊断准确性研究2的质量评估工具进行独立评估。对于荟萃分析,构建了接收器工作特性曲线下的分层汇总区域,并使用随机效应模型进行定量数据合成。
结果:该分析包括25项研究,包括73,981例低风险妊娠,进行妊娠晚期超声评估,其中5380名新生儿(7.3%)出生时小于胎龄。在预测小于胎龄时,估计胎儿体重<10百分位数和腹围<10百分位数的合并敏感性为36%(95%置信区间,27%-46%)和37%(95%置信区间,19%-60%),分别,在32周超声和48%(95%置信区间,41%-56%)和50%(95%置信区间,25%-74%),分别,在36周超声检查。在检测小于胎龄时,估计胎儿体重<10百分位数和腹围<10百分位数的合并特异性为93%(95%置信区间,91%-95%)和95%(95%置信区间,85%-98%),分别,在32周超声和93%(95%置信区间,91%-95%)和97%(95%置信区间,85%-98%),分别,在36周超声检查。在检测小于胎龄时,估计胎儿体重<10百分位数和腹围<10百分位数的诊断优势比为8.8(95%置信区间,5.4-14.4)和11.6(95%置信区间,6.2-21.6),分别,在32周超声和13.3(95%置信区间,10.4-16.9)和36.0(95%置信区间,4.9-260.0),分别,在36周超声检查。汇集的敏感性,特异性,预测胎儿生长受限的诊断比值比为71%(95%置信区间,52%-85%),90%(95%置信区间,79%-95%),和25.8(95%置信区间,14.5-45.8),分别,在32周超声和48%(95%置信区间,41%-55%),94%(95%置信区间,93%-96%),和16.9(95%置信区间,10.8-26.6),分别,在36周超声检查。在预测小于胎龄新生儿时,<10百分位数的腹围似乎与<10百分位数的估计胎儿体重具有相当的敏感性。
结论:对于小于胎龄新生儿,妊娠36周时的超声评估似乎比妊娠32周时的超声评估具有更好的预测准确性。然而,当结局是胎儿生长受限时,观察到相反的趋势.在检测小于胎龄新生儿时,胎儿腹围的预测准确性与估计的胎儿体重相似。