Objective: To investigate the prenatal diagnosis and prognostic factors of fetal sacrococcygeal teratoma (SCT). Methods: A retrospective analysis was performed on 41 pregnant women who were diagnosed with fetal SCT by prenatal ultrasound at the Women's Hospital, Zhejiang University School of Medicine from January 2014 to September 2021. The prenatal imaging features and pregnancy outcomes, including tumor volume to fetal weight ratio (TFR), proportion of solid tumor, tumor growth rate (TGR), fetal hydrops, placentomegaly and polyhydramnios were analyzed. Receiver operating characteristic (ROC) curve was used to determine the critical values of TFR and TGR for predicting adverse fetal outcomes. Results: (1) Among the 41 pregnant women with fetal SCT, the diagnostic gestational week of ultrasound was (24.2±2.9) weeks (range: 18-28 weeks). Among them, 1 case progressed to fetal hydrops and induced labor at 22 weeks of gestation, 1 case developed intrauterine death and induced labor at 29 weeks of gestation, and 39 pregnancies continued until delivery. Among the 39 cases of continued pregnancy, 1 case underwent cesarean section at 31 weeks of gestation due to malignant polyhydramnios and increased fetal cardiothoracic ratio in the third trimester, 1 case underwent cesarean section at 32 weeks of gestation due to fetal heart failure, and 1 case underwent cesarean section at 32 weeks of gestation due to fetal heart failure and hydrops. The other 36 cases underwent surgical resection of tumor within 3 weeks after birth with good prognosis. (2) TFR>0.12 before 28 weeks of gestation could predict poor fetal prognosis, with a sensitivity of 100.0%, a specificity of 86.1% and an area under curve (AUC) of 0.922 (P<0.01). Among the fetuses with TFR>0.12, 5/10 had poor prognosis, while the fetuses with TFR≤0.12 all had good prognosis (100%,31/31), and the difference between the two groups was statistically significant (P<0.001). (3) TGR>48 cm3/week could predict poor fetal prognosis with a sensitivity of 100.0%, a specificity of 78.3% and an AUC of 0.880 (P<0.05). (4) Among the 28 SCT fetuses delivered in our hospital, the incidence rate of poor fetal prognosis was 0 (0/20) in those with solid tumor component<50%, and 5/8 in those with solid tumor component ≥50%, and the difference between the two groups was statistically significant (P<0.01). The incidence rate of poor fetal prognosis was 2/2 in those with placentomegaly (all with fetal hydrops), and 12% (3/26) in those without placentomegaly. The risk of poor fetal prognosis was 8.67 times higher in those with placentomegaly than those without placentomegaly, and the difference between the two groups was statistically significant (P<0.05). The incidence rate of poor fetal prognosis in those with polyhydramnios was 3/7, and 10% (2/21) in those without polyhydramnios, but there was no statistically significant difference between the two groups (P>0.05). Conclusion: TFR combined with solid tumor morphology, TGR, and presence of placentomegaly could predict the adverse pregnancy outcomes of fetal SCT.
目的： 探讨胎儿骶尾部畸胎瘤（SCT）的产前诊断和预后因素。 方法： 回顾性分析2014年1月至2021年9月就诊于浙江大学医学院附属妇产科医院并经产前超声诊断（诊断孕周≤28周）为胎儿SCT且继续妊娠的孕妇41例，分析其产前影像学特征和妊娠结局，包括肿瘤体积与胎儿体重比（TFR）、肿瘤实性部分占比、肿瘤生长速率（TGR）、是否存在胎儿水肿、胎盘增厚以及羊水过多。采用受试者工作特征（ROC）曲线分析确定TFR、TGR预测胎儿不良结局的临界值。 结果： （1）41例妊娠SCT胎儿孕妇的超声诊断孕周为（24.2±2.9）周（范围：18~28周），其中1例孕22周进展为胎儿水肿引产，1例孕29周发生胎儿宫内死亡引产，39例继续妊娠直至分娩。39例继续妊娠的孕妇中，1例因妊娠晚期发生恶性羊水过多、胎儿心胸比增大于孕31周行剖宫产术，1例因胎儿心力衰竭于孕32周行剖宫产术，1例因胎儿心力衰竭合并水肿于孕32周行剖宫产术；其余36例均于新生儿出生后3周内行手术切除肿瘤，预后均良好。（2）妊娠28周前TFR>0.12可预测胎儿预后不良，敏感度为100.0%，特异度为86.1%，曲线下面积（AUC）为0.922（P<0.01）。TFR>0.12的胎儿中，5/10预后不良，而TFR≤0.12的胎儿均预后良好（100%，31/31），两者比较，差异有统计学意义（P<0.001）。（3）TGR>48 cm3/周可预测胎儿预后不良，敏感度为100.0%，特异度为78.3%，AUC为0.880（P<0.05）。（4）28例于本院分娩的SCT胎儿中，肿瘤实性成分<50%者胎儿预后不良的发生率为0（0/20），肿瘤实性成分≥50%者胎儿预后不良的发生率为5/8，两者比较，差异有统计学意义（P<0.01）；胎盘增厚者（均合并胎儿水肿）胎儿预后不良的发生率为2/2，无胎盘增厚胎儿预后不良的发生率为12%（3/26），胎盘增厚者发生胎儿预后不良的风险较无胎盘增厚者高8.67倍，两者比较，差异有统计学意义（P<0.05）。羊水过多者胎儿预后不良的发生率为3/7，无羊水过多者胎儿预后不良的发生率为10%（2/21），两者比较，差异无统计学意义（P>0.05）。 结论： TFR联合实体瘤形态、TGR以及是否存在胎盘增厚可预测胎儿SCT的不良妊娠结局。.