Huang Lin-huan, Fang Qun, Xie Hong-ning, Yang Zhi-yun, Yang Yong-zhong, Shi Hui-juan, Huang Xuan
Fetal Medicine Center, Department of Obstetrics and Gynecology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Zhonghua Yi Xue Za Zhi. 2007 Dec 4;87(45):3178-82.
To investigate the manifestations and prenatal diagnosis of the fetus with shortened long bones.
Ultrasonography was conducted on 57 fetuses with shortened long bones and 62 normal fetuses. Percutaneous umbilical blood sampling was performed on the 57 cases to undergo examination of karyotype and mutation in exon 10 of fibroblast growth factor receptor (FGFR)3 gene. Fetal radiography and autopsy were performed in 30 abnormal induced fetuses.
Among the 57 fetuses of the shortened long bones group 21 (37%) were diagnosed as with specific skeletal dysplasia postnatally, abnormal chromosome were found in 8 (14%), 4 (7%) were with fetal growth restriction, and 24 (42%) were with unknown etiology. Prenatal ultrasonography showed that in the fetuses with skeletal dysplasia the value of standard deviation score (SD) for femur length and/or humerus length fell to -4 SD of the corresponding pregnancy week, and increase of biparietal diameter was often found; in the fetuses with abnormal chromosome and fetal growth restriction (FGR) the degree of bone shortening was between -2 SD to -4 SD; and in the fetuses with lethal skeletal dysplasia the long bones were shortened at the degree more than -8 SD. When the ratio of femur length to abdominal circumference was less than 0.16, the sensitivity and specificity for predicting narrow thorax were 100% and 85.7% respectively.
The causes of fetus with shortened long bones include abnormal chromosome, skeletal dysplasia, and FGR. Femur length and/or humerus length falls below -4SD is almost an indication for skeletal abnormality. When the SD is between -2SD and -4SD, chromosome analysis is necessary and regular ultrasonography is recommended. When the femur length and/or humerus length is below -8SD and femur length/abdominal circumference (FL/AC) is less than 0.16, lethal skeletal dysplasia is suspected.
探讨长骨短小胎儿的表现及产前诊断。
对57例长骨短小胎儿及62例正常胎儿进行超声检查。对57例进行经皮脐血穿刺，检测染色体核型及成纤维细胞生长因子受体（FGFR）3基因第10外显子突变。对30例引产的异常胎儿进行胎儿X线摄影及尸检。
长骨短小组57例胎儿中，21例（37%）出生后诊断为特定骨骼发育不良，8例（14%）染色体异常，4例（7%）胎儿生长受限，24例（42%）病因不明。产前超声检查显示，骨骼发育不良胎儿股骨长度和/或肱骨长度的标准差评分（SD）降至相应孕周的-4SD，常伴有双顶径增大；染色体异常及胎儿生长受限（FGR）胎儿的骨骼缩短程度在-2SD至-4SD之间；致死性骨骼发育不良胎儿长骨缩短程度超过-8SD。当股骨长度与腹围比值小于0.16时，预测胸廓狭窄的敏感度和特异度分别为100%和85.7%。
长骨短小胎儿的病因包括染色体异常、骨骼发育不良及FGR。股骨长度和/或肱骨长度低于-4SD几乎提示骨骼异常。当SD在-2SD至-4SD之间时，需进行染色体分析并建议定期超声检查。当股骨长度和/或肱骨长度低于-8SD且股骨长度/腹围（FL/AC）小于0.16时，怀疑为致死性骨骼发育不良。
