title: Ten-year trends in prevalence of Down syndrome in a developing country: impact of the maternal age and prenatal screening.
abstract: OBJECTIVE
  This study examines trends in total and live birth prevalence of trisomy 21 (T21) with regard to increasing maternal age and the introduction of prenatal diagnosis in Bosnia and Herzegovina.
  
  
  METHODS
  The prenatal detection was introduced in January 2008 in 3 hospitals and assessed until December 31, 2015. In this study, 99 fetuses and 330 babies were diagnosed with T21 in the studied period.
  
  
  RESULTS
  On average, each year 33 T21 individuals were born and 13 T21 fetuses were diagnosed prenatally. The calculated incidence for the live born T21 individuals in Bosnia is 1:999. The live-birth prevalence of T21 was 9.6 per 10,000 births and the total prevalence of T21 was 19.1. The total T21 prevalence increases exponentially with the advanced maternal age. Prenatal T21 prevalence is 1.29 per 10,000 births for mothers <35, but increases exponentially with increasing age (32 for >40 years). The most common indications for invasive prenatal testing were ultrasound screening combined with biochemical serum analysis followed by the advanced maternal age.
  
  
  CONCLUSIONS
  The prevalence of liveborn Down syndrome children remained constant. Despite the fact that increasing maternal age in the last decade contributed to the rise in the total T21 prevalence, the effect of the introduction of prenatal diagnosis on the live-birth T21 prevalence of T21 was minimal, leading to the conclusion that the prenatal screening has to be improved in developing countries.
authors.affiliation: Laboratory of Human Genetics, Department of Pathology, Cytology and Human Genetics, University Clinical Center Sarajevo, Sarajevo, Bosnia and Herzegovina. Electronic address: amina.kozaric@kcus.ba.
authors.forename: Amina
authors.initials: A
authors.lastname: Kurtovic-Kozaric
authors.affiliation: Laboratory of Human Genetics, Department of Pathology, Cytology and Human Genetics, University Clinical Center Sarajevo, Sarajevo, Bosnia and Herzegovina.
authors.forename: Lejla
authors.initials: L
authors.lastname: Mehinovic
authors.affiliation: Department of Medical Genetics, Institute of Laboratory Diagnostics, University Clinical Center of Republic of Srpska, Banjaluka, Bosnia and Herzegovina.
authors.forename: Radmila
authors.initials: R
authors.lastname: Malesevic
authors.affiliation: Laboratory of Cytogenetics, Institute of Pathology, University Clinical Center Tuzla, Tuzla, Bosnia and Herzegovina.
authors.forename: Semir
authors.initials: S
authors.lastname: Mesanovic
authors.affiliation: Department of Medical Genetics, Institute of Laboratory Diagnostics, University Clinical Center of Republic of Srpska, Banjaluka, Bosnia and Herzegovina.
authors.forename: Tijana
authors.initials: T
authors.lastname: Jaros
authors.affiliation: Laboratory of Human Genetics, Department of Pathology, Cytology and Human Genetics, University Clinical Center Sarajevo, Sarajevo, Bosnia and Herzegovina.
authors.forename: Meliha
authors.initials: M
authors.lastname: Stomornjak-Vukadin
authors.affiliation: Center for Genetics, Medical Faculty, University of Sarajevo, Sarajevo, Bosnia and Herzegovina.
authors.forename: Mirela
authors.initials: M
authors.lastname: Mackic-Djurovic
authors.affiliation: Center for Genetics, Medical Faculty, University of Sarajevo, Sarajevo, Bosnia and Herzegovina.
authors.forename: Slavica
authors.initials: S
authors.lastname: Ibrulj
authors.affiliation: Laboratory of Human Genetics, Department of Pathology, Cytology and Human Genetics, University Clinical Center Sarajevo, Sarajevo, Bosnia and Herzegovina.
authors.forename: Ilvana
authors.initials: I
authors.lastname: Kurtovic-Basic
authors.affiliation: Clinic of Obstetrics and Gynecology, University Clinical Center Sarajevo, Sarajevo, Bosnia and Herzegovina.
authors.forename: Mirza
authors.initials: M
authors.lastname: Kozaric
mesh_terms: D017522:Bosnia and Herzegovina / Q000453:epidemiology; D003906:Developing Countries; D004314:Down Syndrome / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D011296:Prenatal Diagnosis; D015995:Prevalence
keywords: Bosnia and Herzegovina; Maternal age; Prenatal diagnosis; Trends; Trisomy 21