Objective: To analyze an occurrence of selected types of birth defects in single and multiple pregnancies in the Czech Republic in 1994-2006 period. Design: A retrospective epidemiological analysis of birth defects according to a multiplicity of pregnancy.
Setting: Department of Medical Genetics, Thomayer's University Hospital, Prague. Chair of Medical Genetics, Postgraduate Medical Institute, Prague.
Methods: Data were collected from National Birth Defects Register (Institute of Health Information and Statistics). Incidences of selected types of birth defects according to pregnancy multiplicity were analyzed.
Results: In 1994-2006, totally 1 132 567 children were born in the Czech Republic, out of which more than 42 000 with a birth defect. In all particular defects, incidences were increased in children born from multiple pregnancies compared to singletons.
Conclusion: Highest differences in birth defects incidences in children born from single versus multiple pregnancies were found in neural tube defects group and in congenital hydrocephalus.