Ben-Haroush Avi, Yogev Yariv, Hod Moshe, Bar Jacob
Perinatal Division, Department of Obstetrics and Gynecology, Rabin Medical Centre, Beilinson Campus, Petah Tiqva 49100, Israel.
Eur J Obstet Gynecol Reprod Biol. 2007 Feb;130(2):187-92. doi: 10.1016/j.ejogrb.2006.04.018. Epub 2006 May 23.
To evaluate the accuracy of ultrasound-based fetal weight estimates made at 28-34 weeks of gestation in predicting small- and large-for-gestational-age infants (SGA, LGA) at term.
Two-hundred and fifty-nine patients with a healthy, singleton pregnancy in whom fetal biometry measurements were routinely performed between 28 and 34 weeks' gestation, were recruited at term delivery. The sonographic estimated fetal weight (EFW) and the birth weight were converted to percentiles on the basis of locally developed growth charts and compared. Multivariate linear stepwise regression analysis was used to predict the birth weight and birth weight percentile. The resulting equation (projectile formula) was used to determine the calculated birth weight, and that value was compared with the actual birth weight. The Bland and Altman plot and Passing and Bablok regression were used to compare between the calculated birth weight and the actual birth weight.
Mean gestational age at ultrasound examination was 32+/-1.6 weeks (28-34), and mean age at delivery was 39+/-1.7 weeks (37-42). The multivariate correlation between the calculated birth weight and the birth weight (R2 = 0.524) was higher than the correlation between the sonographic EFW and the birth weight (R2 = 0.083). Both the sonographic EFW and the calculated birth weight are characterized by low positive predictive values in predicting SGA or LGA infants. The calculated birth weight was more accurate in excluding SGA and LGA infants (negative predictive values of 99.5% and 100%, respectively). On method comparison tests, the calculated birth weight was not significantly different than the actual birth weight.
Fetal weight estimation at the early third trimester poorly predicts the birth weight centile at term. It remains uncertain, however, if it would be useful to use the calculated birth weight in pregnancies with clinically suspected SGA or LGA fetuses.
评估妊娠28 - 34周时基于超声的胎儿体重估计在预测足月小样儿和大于胎龄儿（SGA、LGA）方面的准确性。
招募了259例单胎健康妊娠患者，她们在妊娠28至34周期间常规进行了胎儿生物测量，并在足月分娩时纳入研究。根据当地制定的生长图表，将超声估计胎儿体重（EFW）和出生体重转换为百分位数并进行比较。采用多元线性逐步回归分析来预测出生体重和出生体重百分位数。所得方程（抛射公式）用于确定计算出的出生体重，并将该值与实际出生体重进行比较。使用Bland - Altman图和Passing - Bablok回归来比较计算出的出生体重与实际出生体重。
超声检查时的平均孕周为32 ± 1.6周（28 - 34周），平均分娩年龄为39 ± 1.7周（37 - 42周）。计算出的出生体重与出生体重之间的多元相关性（R² = 0.524）高于超声EFW与出生体重之间的相关性（R² = 0.083）。超声EFW和计算出的出生体重在预测SGA或LGA婴儿方面均具有较低的阳性预测值。计算出的出生体重在排除SGA和LGA婴儿方面更准确（阴性预测值分别为99.5%和100%）。在方法比较测试中，计算出的出生体重与实际出生体重无显著差异。
孕晚期早期的胎儿体重估计对足月时的出生体重百分位数预测不佳。然而，对于临床怀疑有SGA或LGA胎儿的妊娠，使用计算出的出生体重是否有用仍不确定。
