探讨超声在胎儿外生殖器异常产前诊断中的临床意义。

对2014年1月至2016年1月北京大学第三医院超声诊断和疑诊14例外生殖器异常胎儿的产前超声表现、产后生殖器形态特征及病理结果进行分析。

14例外生殖器异常胎儿产前超声表现及临床结局：（1）部分性阴茎阴囊转位4例（28.6%，4/14），产前胎儿外生殖器共同的声像图表现为短小的阴茎位于分裂的阴囊之间，呈"花瓣"征，均合并阴茎短小、尿道下裂，其中2例终止妊娠（1例合并一侧输尿管扩张、肾积水、肛门闭锁；1例合并室间隔缺损），1例未合并其他异常，足月自然分娩，1例合并隐性脊柱裂，足月自然分娩。（2）完全性阴茎阴囊转位2例（14.3%，2/14），产前超声表现为阴茎与阴囊的位置完全颠倒，即阴茎在阴囊之后，阴茎指向尾侧；其中1例合并肛门闭锁、小眼球畸形，1例合并法洛四联症、十二指肠闭锁、肛门闭锁，超声检查后孕妇均选择终止妊娠。（3）阴茎短小4例（28.6%，4/14），产前超声表现为阴茎形态结构显示困难或仅呈点状中等回声，其中2例胎儿宫内生长受限；1例生后不明原因死亡，1例生后存在尿道下裂；另2例胎儿中1例染色体核型为18-三体，1例9号染色体微缺失，超声检查后孕妇均选择终止妊娠。（4）阴茎缺如2例（14.3%，2/14），产前超声仅探及胎儿阴囊结构，阴茎缺如，均合并膀胱外翻，超声检查后孕妇均选择终止妊娠。（5）外生殖器性别不明2例（14.3%，2/14），1例染色体核型为46xy，出生后呈女性生殖器外观，1例染色体为46xx，出生后随访患者自诉阴蒂肥大，患先天性肾上腺皮质增生症。

产前超声检查是诊断胎儿外生殖器畸形有效、可行的检查方法，阴茎阴囊转位、阴茎缺如可产前诊断；在超声检查中胎儿性别难以明确时，应结合染色体检查以识别是否存在外生殖器畸形。因声像图不典型而诊断困难者，在不合并其他异常时应慎重诊断，可于中晚孕期再次超声检查而明确诊断。

To explore the clinical significance of abnormal fetal genitalia detected by routine prenatal ultrasound.

In Peking University Third Hospital from January 2014 to January 2016, the ultrasonic diagnosis and sonographic features in 14 suspected cases of abnormal fetal genitalia were analyzed retrospectively and compared with postpartum morphological and pathological characteristics.

The fetal ultrasound findings and clinical outcomes in 14 cases were: (1) There were 4 cases of partial penoscrotal transposition (28.6%, 4/14), in which all fetus hadshort penis and hypospadias. In 2 termination cases, unilateral hydronephrosis and anal atresia was found in one case, while ventricular septal defect was found in the other case. In 2 term-birth cases, there was one case of recessive spina bifida. In the 4 cases, prenatal ultrasonographic manifestation showed that the short penis was located between the division of the scrotum, named as ″tulip sign″. (2) There were 2 cases (14.3%, 2/14) of complete penoscrotal transposition, in which all the pregnancies were terminated. On prenatal ultrasound of external genitalia, the location of the penis and scrotum was reversed. In one case, anal atresia and small eye malformation were found. In one case, the tetralogy of Fallot, duodenal atresia and anal atresia were found. (3) There were 4 cases of the micropenis (28.6%, 4/14). On prenatal ultrasound, the penis was difficult to demonstrated and was shown merely as an echoic dot. Among 2 cases of FGR, one infant dies for unexplained reasons after birth, and one infant has hypospadias after birth. The pregnancy was terminated in two cases of 18-trisomia and microdeletion in chromosome 9. (4) There were 2 cases of penis absence (14.3%, 2/14), in which all pregnancies were terminated. The sonographic manifestations show the absence of penis and bladder eversion. (5) In 2 cases, sex couldn`t be identified (14.3%, 2/14). In one case, the 46 xy infant showed a female external genitalia appearance after birth. In one case, the clitorism and congenital adrenal cortical hyperplasia were found in a 46 xx infant after birth.

Prenatal ultrasonography is effective and feasible in detecting genitalia abnormalities, especially for penis scrotal transposition and penis absence. When the fetal gender cannot be identified on ultrasound, chromosome examination is warranted. For indeterminable cases, ultrasound follow-up in 2^nd and 3^rd trimester is necessary.