摘要本文报告了1例妊娠14周经超声发现胎儿骶尾部畸胎瘤，超声联合MRI提示肿瘤分型为Ⅰ型。妊娠26周前肿瘤囊性部分占比>60%，妊娠28周肿瘤囊性部分自行破裂。妊娠期密切监测，妊娠36周 +5时，肿瘤体积增至12.8 cm×9.7 cm×12.3 cm。孕妇于妊娠37周行剖宫产术分娩。新生儿生后4 d于小儿外科行肿瘤切除术，术后随访无生理功能障碍，预后良好。

abstractsWe describe a case of fetal sacrococcygeal teratoma detected by ultrasound at 14 gestational weeks. The tumor was classified as "type Ⅰ" by ultrasonography combined with MRI. The cystic part accounted for over 60% of the mass before 26 weeks and ruptured spontaneously at 28 weeks. The size of the tumor was 12.8 cm×9.7 cm×12.3 cm at 36 +5 gestational weeks. A female newborn was born through cesarean section at 37 weeks of gestation and had the tumor removed surgically on the postnatal day 4. Postoperative follow-up showed that the neonate had a good prognosis without physiological dysfunction.