Department of Obstetrics and Gynaecology, Nelson R Mandela School of Medicine, University of Kwa-Zulu Natal, South Africa.
Ultrasound Obstet Gynecol. 2009 Nov;34(5):503-9. doi: 10.1002/uog.7348.
To create reference intervals of gestational sac volume (GSV), yolk sac volume (YSV), embryo volume (EV), crown-rump length (CRL) and gestational sac diameter (GSD) in the first trimester of pregnancy using three-dimensional ultrasound.
Women in the first trimester of pregnancy were invited to participate in the study. Inclusion criteria were well-established dates, and that the women were non-smokers and healthy, without any medical disorders. Three-dimensional ultrasound volumetric data (GSV, YSV, EV) were collected together with standard two-dimensional measurements of CRL and GSD. For each measurement separate regression models were fitted to estimate the mean and SD at each gestational age. The 5(th), 50(th) and 95(th) centiles were derived using a combination of these regression models.
One hundred and sixty-six women at between 6 and 12 weeks' gestation were scanned once. The mean ( +/- SD) maternal age was 29.4 ( +/- 5) years. There were no miscarriages and no congenital abnormalities were noted. Mean gestational age at delivery was 39.3 ( +/- 1.4) weeks and mean birth weight was 3.3 ( +/- 0.4) kg. The CRL centiles fitted a cubic model and the GSD centiles fitted a linear model. The centiles for YSV fitted a quadratic model on the modified log-transformed data. The centiles for GSV and EV were modeled using quantile regression.
Reference intervals and centile charts for first-trimester GSV, YSV and EV have been created in addition to CRL and GSD using rigorous methodology.
使用三维超声技术建立妊娠早期孕囊体积（GSV）、卵黄囊体积（YSV）、胚胎体积（EV）、头臀长（CRL）和孕囊直径（GSD）的参考区间。
邀请妊娠早期的妇女参加这项研究。纳入标准为明确的孕龄，且妇女为不吸烟且健康，无任何医学疾病。收集三维超声容积数据（GSV、YSV、EV）以及标准的二维CRL 和 GSD 测量值。对于每个测量值，分别拟合回归模型以估计每个孕龄的均值和标准差。使用这些回归模型的组合得出第 5、50 和 95 百分位数。
166 名 6-12 周妊娠的妇女接受了一次扫描。平均（ +/- SD）母亲年龄为 29.4（ +/- 5）岁。无流产，也未发现先天性异常。分娩时的平均孕龄为 39.3（ +/- 1.4）周，平均出生体重为 3.3（ +/- 0.4）kg。CRL 百分位数拟合三次模型，GSD 百分位数拟合线性模型。YSV 的百分位数在经过修正对数转换的数据上拟合二次模型。GSV 和 EV 的百分位数使用分位数回归进行建模。
使用严格的方法除了 CRL 和 GSD 之外，还为妊娠早期的 GSV、YSV 和 EV 建立了参考区间和百分位数图表。
