Deter R L, Harrist R B, Hadlock F P, Poindexter A N
Am J Obstet Gynecol. 1982 Jul 1;143(5):545-54. doi: 10.1016/0002-9378(82)90545-2.
To characterize the growth of individual fetuses, serial measurements of the crown-rump length (CRL), biparietal diameter (BPD), head circumference (HC), and abdominal circumference (AC) were made at specified intervals of 2 to 3 weeks (between 6 to 8 weeks [conceptual age] and delivery) in 20 normal fetuses with known dates of conception. Values for the HC-AC ratio and the estimated fetal weight were also obtained from these data. Measurements of CRL were similar to those reported previously, except in those cases in which the follicular phase was prolonged or the fetal growth potential was reduced. Mathematical modeling demonstrated that the linear-cubic model was optimal for the BPD and HC growth curves, the linear model for the AC, and the linear-quadratic model for fetal weight. The HC-AC ratio could not be modeled adequately because of significant individual variability. Optimal models for average longitudinal growth curves were determined for the BPD, HC, AC, and fetal weight from individual growth curves. These average longitudinal curves were similar in shape, mean values, and variability to those obtained in previous cross-sectional studies. Statistical analysis indicated that the coefficients of the average longitudinal curves are not likely to change by more than 5% to 15% if the size of the sample is increased very significantly. These results indicate that the average longitudinal growth curves are good estimators of the true population growth curves.
为了描述个体胎儿的生长情况，在20例已知受孕日期的正常胎儿中，于孕6至8周（孕龄）至分娩期间，每隔2至3周对顶臀长（CRL）、双顶径（BPD）、头围（HC）和腹围（AC）进行系列测量。还从这些数据中获取了HC-AC比值和估计胎儿体重的值。CRL的测量结果与先前报道的相似，但在卵泡期延长或胎儿生长潜能降低的情况下除外。数学建模表明，线性-立方模型对BPD和HC生长曲线最为合适，线性模型对AC合适，线性-二次模型对胎儿体重合适。由于个体差异显著，HC-AC比值无法进行充分建模。根据个体生长曲线确定了BPD、HC、AC和胎儿体重的平均纵向生长曲线的最佳模型。这些平均纵向曲线在形状、平均值和变异性方面与先前横断面研究中获得的曲线相似。统计分析表明，如果样本量显著增加，平均纵向曲线的系数变化不太可能超过5%至15%。这些结果表明，平均纵向生长曲线是真实总体生长曲线的良好估计值。
