Impact of prenatal screening on the prevalence of Down syndrome in Slovenia

• Published in: PloS one 2017-06, Vol.12 (6), p.e0180348-e0180348
• Main Authors: Rudolf, Gorazd, Tul, Nataša, Verdenik, Ivan, Volk, Marija, Brezigar, Anamarija, Kokalj Vokač, Nadja, Jeršin, Nataša, Prosenc, Bernarda, Premru Sršen, Tanja, Peterlin, Borut
• Format: Article
• Language: English
• Subjects: Babies; Biology and Life Sciences; Diagnosis; Diagnostic systems; Down syndrome; Down Syndrome - diagnosis; Down Syndrome - epidemiology; Down's syndrome; Female; Fetuses; Genetic aspects; Genetic screening; Health risk assessment; Humans; Infant, Newborn; Infants; Laboratories; Maternal Age; Medical diagnosis; Medicine and Health Sciences; Neonates; Pregnancy; Prenatal development; Prenatal Diagnosis; Prevalence; Prevalence studies (Epidemiology); Research and Analysis Methods; Risk factors; Screening; Slovenia - epidemiology; Trisomy; Ultrasonic imaging; Womens health
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0180348

To evaluate the impact of prenatal screening and genetic testing for trisomy 21 (T21) on the prevalence of T21 in Slovenia. Data about all prenatally and postnatally confirmed cases of T21 in Slovenia between 1981 and 2012 were collected retrospectively from all genetic laboratories in Slovenia. The expected number of babies with T21 according to maternal age was calculated. The primary outcomes measures were number of fetuses and newborn infants with T21 diagnosed prenatally and postnatally and the impact of advances in screening and genetic diagnostics on the prevalence of newborns with T21 in Slovenia. Despite a significantly increased mean maternal age from 25.4 years in year 1981 to 30.3 years in year 2012 the prevalence of newborn infants with T21 was 0.51 per 1000 births compared to 0.55 per 1000 births, respectively. The prevalence of prenatally diagnosed cases increased from 0.03 per 1000 births to 2.06 per 1000. The detection rate of T21 in year 2012 was 78,9%. The total number of prenatal invasive procedures (chorionic villous sampling and amniocenteses) carried out during that period was rising until 2002, since when it is stable at around 7%. The advancement and implementation of screening tests and prenatal diagnostic procedures in Slovenia caused an important improvement in the efficiency of the prenatal detection of T21.