Bennett G L, Bromley B, Benacerraf B R
Department of Radiology, Massachusetts General Hospital, Boston, Mass., USA.
Radiology. 1996 May;199(2):447-50. doi: 10.1148/radiology.199.2.8668792.
To determine whether agenesis of the corpus callosum can be diagnosed prenatally with standard ultrasonographic (US) evaluation before 22 weeks of gestation.
Initial scans obtained on or before 22 weeks and follow-up scans obtained in the third trimester were selected from all cases of agenesis of the corpus callosum diagnosed prenatally at the authors' laboratory. Follow-up was attained by means of review of the medical records and included imaging, karyotype, and clinical outcome.
Among 15 fetuses with callosal agenesis confirmed by means of third-trimester scans, 10 had completely normal US scans at 16-22 weeks and five had other US abnormalities. Isolated callosal agenesis was identified in six children with normal development (except one with polydactyly). Among the others, four were developmentally delayed, three died, and two others had abnormal karyotype.
Standard second-trimester US before 22 weeks of gestation may not show isolated callosal agenesis. Fetuses with this abnormality can have normal second-trimester scans and develop abnormal US findings in the third trimester.
确定在妊娠22周前通过标准超声（US）评估能否产前诊断胼胝体发育不全。
从作者实验室产前诊断为胼胝体发育不全的所有病例中，选取妊娠22周及以前进行的初次扫描以及妊娠晚期进行的随访扫描。通过查阅病历进行随访，包括影像学检查、核型分析和临床结局。
在15例经妊娠晚期扫描确诊为胼胝体发育不全的胎儿中，10例在16 - 22周时超声扫描完全正常，5例有其他超声异常。6例发育正常（除1例多指畸形）的儿童被诊断为孤立性胼胝体发育不全。在其他病例中，4例发育迟缓，3例死亡，另外2例核型异常。
妊娠22周前的标准孕中期超声检查可能无法显示孤立性胼胝体发育不全。患有这种异常的胎儿在孕中期扫描可能正常，但在妊娠晚期会出现异常的超声表现。
