Analysis of the changing birth prevalence of neural tube defects in Hungary.

The birth prevalence of neural tube defects had a significant decrease in Hungary from the sixties till 1978. After this a slight but not significant increase was registered. The changing pattern had no correlation with the developmental (different groups of neural tube defects, still- and livebirth rate, sex ratio, birth weight distribution and twin rate), demographic (monthly and territorial distribution, maternal age, birth order) and medical (prevention program, genetic counselling) factors. There was only one obvious finding, a negative correlation with the standard of living of the population.