Birth Defects Registration in the Czech Republic: Past and Present

Summary

Aim of study:
Analysis of the occurrence of total birth defects, as well as their relative rates, in the Czech Republic between 1981 and 2006. A comparison of observed and expected incidences from the same time period.

Type of study:
Retrospective epidemiologic analysis of data from 1981 to 2006 from the Czech Republic.

Methodology:
Expected (E) incidences from 1981–2006 were calculated from the mean observed (O) incidences from 1961–1980 and from actual annual birth numbers from 1981–2006. These E incidences were compared to O incidences from the same period (1981–2006). O/E >1 means that the number of diagnosed birth defects is higher than the number expected, i.e. the incidence of a particular birth defect is increasing and vice versa for O/E<1.

Results and conclusion:
In the Czech Republic, birth defect registration on a national scale has taken place since 1961. There are currently more types of birth defect being registered than a few decades ago, which is regarded as the main cause of a recent increase in total birth defect incidence. However, incidences of some particular birth defects are decreasing as a result of advances in prenatal diagnosis and related screening programmes (neural tube defects, congenital heart and abdominal wall defects, some chromosomal syndromes etc.).

On the other hand, the incidences of certain birth defects have increased in recent years which may be due to better diagnostic ascertainment or due to more available and widespread screening programmes and techniques (congenital hydrocephalus, kidney defects e.g.) or perhaps there is a “true” increase as has been shown for hypospadia, oesophageal defects or anorectal atresia.

Key words:
birth defect, prenatal diagnostics, epidemiology, anencephaly, spina bifida, encephalocele, neural tube defects, congenital hydrocephalus, omphalocele, gastroschisis, abdominal wall defects, diaphragmatic hernia, renal agenesis/hypoplasia, cystic kidney, congenital oesophageal defects, anorectal malformations, cleft palate, cleft lip and/or palate, facial clefts, Down syndrome, Czech Republic.