目的:准确评估孕龄(GA)在个体和人群水平上都很重要。在怀孕后期预订的女性中估计GA的最准确方法尚不清楚。这项研究的目的是在外部验证妊娠晚期GA估算方程的准确性,并确定在第二或第三个三个月之前未接受超声扫描的女性中估算GA的最佳方程。
方法:这是一个前瞻性的,观察性横断面研究。
方法:57个产前护理中心,法国。
方法:在8周的时间内招募了单胎妊娠和先前11-14周约会扫描的女性。他们在怀孕期间的一个时间点(15-43周)接受了标准化的超声检查,测量12个胎儿生物特征参数,这些参数先前已被确定为对GA估计有用。
方法:检查了总共189个基于胎儿生物统计学估计GA的方程,并将其与基于胎儿CRL的GA估计进行了比较。使用R2、校准斜率和截距进行观察到的GA和估计的GA之间的比较。RMSE,还计算了平均差和95%的误差范围.
结果:共检查了2741名孕妇。排除后,包括2339名参与者。在20个表现最好的方程中,截距范围为-0.22至0.30,校准斜率为0.96至1.03,RSME为0.67至0.87。总的来说,多参数模型优于单参数模型。95%的误差范围和平均差均随妊娠而增加。仅基于头围测量的常用模型不在表现最好的模型中,并且与较高的95%误差和平均差相关。
结论:我们提供了强有力的证据,表明应使用基于多参数模型的GA特异性方程来估计妊娠晚期的GA。然而,由于妊娠晚期的所有GA评估方法都与较大的预测间隔相关,改善早期产前超声检查的努力必须仍然是优先事项。
背景:本研究的提案和相应的方法学综述已在PROSPERO国际系统综述登记册上注册(注册号:CRD4201913776)。
OBJECTIVE: Accurate assessment of gestational age (GA) is important at both individual and population levels. The most accurate way to estimate GA in women who book late in pregnancy is unknown. The aim of this study was to externally validate the accuracy of equations for GA estimation in late pregnancy and to identify the best equation for estimating GA in women who do not receive an ultrasound scan until the second or third trimester.
METHODS: This was a prospective, observational cross-sectional study.
METHODS: 57 prenatal care centres, France.
METHODS: Women with a singleton pregnancy and a previous 11-14-week dating scan that gave the observed GA were recruited over an 8-week period. They underwent a standardised ultrasound examination at one time point during the pregnancy (15-43 weeks), measuring 12 foetal biometric parameters that have previously been identified as useful for GA estimation.
METHODS: A total of 189 equations that estimate GA based on foetal biometry were examined and compared with GA estimation based on foetal CRL. Comparisons between the observed GA and the estimated GA were made using R2, calibration slope and intercept. RMSE, mean difference and 95% range of error were also calculated.
RESULTS: A total of 2741 pregnant women were examined. After exclusions, 2339 participants were included. In the 20 best performing equations, the intercept ranged from -0.22 to 0.30, the calibration slope from 0.96 to 1.03 and the RSME from 0.67 to 0.87. Overall, multiparameter models outperformed single-parameter models. Both the 95% range of error and mean difference increased with gestation. Commonly used models based on measurement of the head circumference alone were not amongst the best performing models and were associated with higher 95% error and mean difference.
CONCLUSIONS: We provide strong evidence that GA-specific equations based on multiparameter models should be used to estimate GA in late pregnancy. However, as all methods of GA assessment in late pregnancy are associated with large prediction intervals, efforts to improve access to early antenatal ultrasound must remain a priority.
BACKGROUND: The proposal for this study and the corresponding methodological review was registered on PROSPERO international register of systematic reviews (registration number: CRD4201913776).