Neural Tube Defects in the Czech Republic: Incidence, Prenatal Diagnosis and Sex Distribution

Neural tube defects (NTDs) represent frequent and severe congenital anomalies of the central nervous system, including anencephaly, spina bifida, and encephalocele. This retrospective study evaluates the occurrence, prenatal diagnosis, and sex distribution of NTDs in the Czech Republic during the period 1961-2020. Data were obtained from the National Registry of Congenital Anomalies within the National Registry of Reproductive Health. Both prenatally and postnatally diagnosed cases of anencephaly, spina bifida, and encephalocele were analyzed. A total of 2,521 cases of anencephaly, 3,391 cases of spina bifida, and 704 cases of encephalocele were recorded. Prenatal diagnosis with subsequent termination of pregnancy accounted for a substantial proportion of cases, particularly in anencephaly. The mean total incidence per 10,000 live births was 2.91 for anencephaly, 4.38 for spina bifida, and 1.24 for encephalocele. Sex distribution analysis across six consecutive decades demonstrated a persistent predominance of affected females in spina bifida, with statistically significant differences in selected periods. In contrast, anencephaly and encephalocele showed a female predominance only in earlier decades, whereas a higher proportion of affected males has been observed in recent years. Although advances in prenatal diagnostics have markedly reduced the incidence of NTDs among live-born children, the overall population incidence of these defects has remained stable.