Incidence of congenital microcephaly in the Czech Republic: The effect of maternal age.

Objective: Congenital microcephaly is a diverse group of congenital anomalies characterized by a significantly reduced head circumference at birth. The incidence varies widely across regions. This study focuses on the incidence of microcephaly in the Czech Republic.

Methods: A retrospective analysis was conducted using data from the National Registry of Congenital Anomalies of the Czech Republic. All cases coded as microcephaly (Q02 code in the 10th revision of the International Classification of Diseases) between 2000 and 2020 were included.

Results: A total of 274 cases of congenital microcephaly were identified, with an incidence rate of 1.22 per 10,000 births. The sex ratio was significantly skewed toward females (0.63:0.37). Microcephaly was significantly more frequent among mothers aged less than 25 years (1.68 per 10,000) and over 35 years (1.51 per 10,000), compared to those aged 25-34 years (1.03 per 10,000).

Conclusion: This research provides the most detailed population-based estimate of congenital microcephaly in the Czech Republic. The study reports a lower relative incidence compared to many other countries. The findings highlight significant associations with maternal age and a notable female predominance, warranting further investigation into genetic and biological mechanisms.