摘要：
Objective To explore the clinical value of prenatal ultrasonography in the differentiation among the etiologies of fetal megacystis.Methods Twenty seven fetuses,diagnosed as fetal megacystis by prenatal ultrasonography,were retrospectively analyzed.The etiologies of fetal megacystis were presumed by such characteristics as keyhole sign,thickness of the bladder wall,amniotic fluid index,fetal sex and other combined signs.All fetuses were followed up until to the induction of labor or birth.Results Twenty seven singleton fetuses (19 males and 8 females) were diagnosed as megacystis.According to the characteristics and other combined signs,8 cases of posterior urethral valves (PUV),1 of prune belly syndrome(PBS),1 of megacystis-microcolon intestinal hypoperistalsis syndrome(MMIHS),1 of urethral atresia and 5 of chromosomal abnormality were presumed by prenatal ultrasound.Multiple malformations were found in 5 fetuses and there were also 6 fetuses with unknown reason originally.Among the 27 fetuses,21 were induced labor and 6 continued pregnancy to birth.Except for the 6 cases of unknown reason,etiologies of 17 fetuses with megacystis were confirmed by autopsy,genetic tests,surgery or further examination after birth.The accuracy rate of prenatal ultrasonography in the differentiation among the etiologies of fetal megacystis was 80.95％ (17/21).Conclusions On the basis of detailed prenatal ultrasonography and typical characteristics,it is reliable to differentiate the etiologies of fetal megacystis.Sometimes fetal megacystis may be one part of multiple malformations or complex syndrome,such as VACTERL syndrome.However,it is difficult for ultrasonography to diagnose vesicoureteral reflux(VUR)prenatally.%目的 探讨产前超声在鉴别胎儿巨膀胱病因中的应用价值.方法 回顾性分析产前超声诊断为巨膀胱的27例胎儿,根据“钥匙孔”征、膀胱壁厚度、羊水指数、胎儿性别四大特征及合并征象推测导致巨膀胱的病因,并随访至出生后或引产后.结果 27例巨膀胱胎儿均为单胎妊娠,其中男性胎儿19例,女性胎儿8例.根据以上四大特征及是否合并其他异常,产前推测后尿道瓣膜(posterior urethral valves,PUV)8例,梅干腹综合征(prune belly syndrome,PBS)1例,巨膀胱-小结肠-肠蠕动迟缓综合征(megacystis-microcolon-intestinal hypoperistalsis syndrome,MMIHS)1例,尿道闭锁1例,染色体异常5例,另产前超声发现多发畸形5例,亦有6例原因不明.27例胎儿中6例继续妊娠至足月出生,21例引产.除6例产前超声不能明确病因的巨膀胱胎儿外,17例胎儿巨膀胱的病因经引产、遗传学检测或出生后检查或手术证实,产前超声推测胎儿巨膀胱病因的符合率为80.95％ (17/21).结论根据详细的产前超声检查及四大特征:“钥匙孔”征、膀胱壁厚度、羊水指数、胎儿性别,可较可靠地鉴别导致胎儿巨膀胱的病因.部分巨膀胱为复杂综合征如VACTERL综合征的一个超声表现,然而产前不易诊断膀胱输尿管反流.
