Grennert L, Persson P H, Gennser G
Acta Obstet Gynecol Scand Suppl. 1978;78:28-32. doi: 10.3109/00016347809162699.
Both earlier growth charts of twins composed of birth weight at different gestational ages and recent reports on twin biparietal diameter (BPD) growth, indicate that twins' growth is less than that of singletons during the later period of gestation. In the present study, growth curves are constructed separately for the first and the second twin from 489 paired ultrasonic BPD measurements of 119 twin pregnancies. The distribution of BPD values in twins was found to be slightly wider than our normal range curve for singletons. The mean BPD values of twins were close to those of singletons in the second trimester. From the 32nd week on, the twins' mean weekly BPD increment decreased, this lesser growth rate being more marked than that of singletons. The second twin's BPD growth curve ran consistently below that of the first. Our results agree with the earlier findings that the growth of twins is retarded during the later part of pregnancy. They point to different BPD growth patterns between the first and the second twin.
早期由不同孕周出生体重构成的双胞胎生长图表以及近期关于双胞胎双顶径（BPD）生长的报告均表明，在妊娠后期双胞胎的生长速度低于单胎。在本研究中，从119例双胎妊娠的489对超声BPD测量值中，分别为第一和第二胎儿构建生长曲线。发现双胞胎BPD值的分布范围比我们单胎的正常范围曲线略宽。双胞胎的平均BPD值在孕中期接近单胎。从第32周起，双胞胎的平均每周BPD增长幅度下降，这种较低的生长速度比单胎更为明显。第二胎儿的BPD生长曲线一直低于第一胎儿。我们的结果与早期研究结果一致，即双胞胎在妊娠后期生长发育迟缓。它们表明第一和第二胎儿之间存在不同的BPD生长模式。
