Growth velocity of fetal sacrococcygeal teratoma as predictor of perinatal morbidity and mortality: multicenter study

Objective: To identify prenatal predictors of poor perinatal outcome in fetuses with isolated sacrococcygeal teratoma (SCT).

Methods: This was a retrospective study of fetuses with isolated (non-syndromic) SCT managed at one of five pediatric surgery and/or fetal medicine centers between January 2007 and December 2017. The primary outcome was the occurrence of poor perinatal outcome, defined as prenatal death (including termination), or neonatal death or severe compromise (hemorrhagic shock). Data regarding prenatal diagnosis (sonographic features both at referral and at the last ultrasound examination before pregnancy outcome, assessment of SCT growth velocity), perinatal complications and outcome, and neonatal course were analyzed to determine prenatal SCT characteristics associated with adverse perinatal outcome.

Results: Fifty-five fetuses were included, diagnosed with isolated SCT at a median gestational age of 22 (interquartile range, 18-23) weeks. There was a poor perinatal outcome in 31% (n = 17) of these cases, including intrauterine fetal demise (4%, n = 2), pregnancy termination (13%, n = 7) and neonatal severe compromise (15%, n = 8), leading to neonatal death in five cases. The overall survival rate after prenatal diagnosis of isolated SCT was 75% (n = 41 of 55). Earlier gestational age at diagnosis (P = 0.02), large tumor volume at referral (P < 0.001), presence of one or more hemodynamic complications (P = 0.02), fast tumor growth velocity (P < 0.001) and high tumor grade (highest tumor grade ≥ 3) (P = 0.049) were associated with poor perinatal outcome on univariate analysis. On stepwise logistic regression analysis, tumor growth velocity was the only remaining independent factor associated with poor perinatal outcome (odds ratio (OR) (per 1-mm/week increase), 1.48 (95% CI, 1.22-1.97), P = 0.001). The best predictive cut-off of tumor growth velocity for poor perinatal outcome was 7 mm/week (OR, 25.7 (95% CI, 5.6-191.3), P < 0.001), yielding a sensitivity of 88% and a specificity of 77%.

Conclusions: Approximately 30% of fetuses with a diagnosis of isolated SCT have poor perinatal outcome. Tumor growth velocity ≥ 7 mm/week appears to be an appropriate discriminative cut-off for poor perinatal outcome. These results could help to inform prenatal management and counseling of parents with an affected pregnancy. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.