Prenatal diagnostics of birth defects in the Czech Republic – a fifteen-year period

Czech version

Authors: V. Gregor ¹; A. Šípek ^1,2,4; J. Horáček ^1,5; A. Šípek ⁶; P. Langhammer ⁷
Authors‘ workplace: Oddělení lékařské genetiky, Thomayerova nemocnice, Praha, ředitel MUDr. K. Filip, CSc., MBA ¹; Oddělení lékařské genetiky, Sanatorium Pronatal, odborný vedoucí doc. MUDr. T. Mardešic’, CSc. ²; Katedra lékařské genetiky, Institut postgraduálního vzdělávání ve zdravotnictví, Praha, ředitel MUDr. V. Pavelka ³; Ústav obecné biologie a genetiky 3. LF UK, Praha, děkan prof. MUDr. Michal Anděl, CSc. ⁴; Gennet, Praha, vedoucí MUDr. D. Stejskal ⁵; Ústav biologie a lékařské genetiky 1. LF UK a VFN, Praha, doc. MUDr. M. Kohoutová, CSc. ⁶; Ústav zdravotnických informací a statistiky České republiky, ředitel Mgr. J. Holub ⁷
Published in: Ceska Gynekol 2012; 77(5): 437-444

Overview

Aim of study:
An analysis of prenatal and postnatal incidences of selected birth defects and secondary prevention efficiency in the Czech Republic in 1994 – 2008 period.

Type of study:
Retrospective epidemiological analysis of birth defects data from particular centers of clinical genetics and prenatal diagnostics (prenatal data) and from the Czech National Birth Defects Register database (birth data).

Material and methods:
Data from the National Birth Defects Register (Institute for Health Information and Statistics of the Czech Republic) were used along with data from particular centers of clinical genetics and prenatal diagnostics covering the whole area of the Czech and the 1994 – 2008 period. Total prenatal diagnostics efficiency and an efficiency of prenatal diagnostics of 5 selected defects (anencephaly, spina bifida, omphalocele, gastroschisis and Down syndrome) were studied.

Results:
In the period under study the number of prenatally diagnosed birth defects has increased. In 1994, the incidence of prenatally diagnosed (and selectively terminated) birth defects was 27.40 per 10 000 live births while in 2008 it was 73.26 per 10 000. In prenatally diagnosed but not terminated defects the corresponding numbers were 8.91 in 1994 and 32.87 in 2008. In last years, a quality change in prenatal birth defects screening has taken place in the Czech Republic. A first trimester screening with an increased efficiency not only for Down syndrome (DS) has been used more often implicating a wider application of chorionic villi sampling (CVS). An increased screening efficiency also made possible a relative decrease of invasive prenatal diagnostics procedures necessary to diagnose a single case of Down syndrome. When comparing CVS and amniocentesis from this particular point of view a higher CVS efficiency (about 12 CVS versus some 120 amniocenteses per 1 case of DS).

Prenatal diagnostics efficiency has increased in all defects under study over the 1994 – 2008 period, being about 80% in DS almost 10% in anencephaly, 65 – 68% in omphalocele and gastroschisis and 80% in spina bifida in last years.

Conclusions:
Chromosomal aberration (DS especially) are among the most frequent prenatally diagnosed birth defects, further being heart defects, neural tube defects (anencephaly, encephalocele, spina bifida), hydrocephalus, congenital skeletal system defects, abdominal wall defects (omphalocele, gastroschisis) and renal defects. In some defects, prenatal diagnostics has also significantly influenced their incidence in births (anencephaly, gastroschisis and DS e.g.).

Key words:
birth defect, incidence, prenatal diagnostics, anencephaly, spina bifida, omphalocele, gastroschisis, Down syndrome, amniocentesis, chorionic villi sampling, Czech Republic.