High prevalence of sacrococcygeal teratoma in Finland - a nationwide population-based study.

AIM: The birth prevalence of sacrococcygeal teratoma (SCT) has been reported to range from 1:27 000 to 1:40 000. We assessed the population-based prevalence and clinical presentation of SCT over 22 years. METHODS: We identified all cases of SCT, including live births, stillbirths and terminations of pregnancy (TOPs), in the Finnish Register of Congenital Malformations, covering 1987-2008. Data on prenatal diagnoses, pregnancy outcomes, infant deaths and associated anomalies were collected. RESULTS: One hundred and twenty four SCT cases were identified among 1 331 699 pregnancies. There were 89 (72%) live births, 13 (10%) stillbirths and 22 (18%) TOPs. The total prevalence of SCT was 1:10 700. Tumours were detected in utero in 55% of the pregnancies with SCT. The proportion of perinatal deaths among all SCT births was 28%. Thirty percentage of the cases had associated abnormalities (mainly of the urinary tract and various syndromes). CONCLUSION: This nationwide, population-based study on SCT shows that the total and birth prevalence of SCT in Finland is markedly higher than previously reported. This may reflect true differences between populations, but may also be explained by accurate nationwide registration of SCTs. The high perinatal mortality rate has an impact on counselling of families and planning of deliveries.