title: Frequency of fetal karyotype abnormalities in women undergoing invasive testing in the absence of ultrasound and other high-risk indications.
abstract: OBJECTIVE
  No previous studies have reported the frequencies of individual chromosomal anomalies in normal-appearing fetuses stratified by maternal age (MA) and gestational age (GA). We therefore sought to (1) characterize the frequency of all fetal karyotype anomalies in sonographically normal appearing fetuses without pretest risk factors, and (2) assess MA and GA impact on the proportion of anomalies targeted by screening and consequent impact on residual risk following a negative result.
  
  
  METHODS
  Fetal karyotypes from samples without prior risk assessment or ultrasound anomalies were analyzed. We calculated, per single-year MA and in two GA intervals, the predicted frequency of each cytogenetic defect.
  
  
  RESULTS
  A total of 129 263 karyotypes were analyzed. The risk for significant, cytogenetically visible chromosomal anomalies, at 15 to 20 weeks GA, varies between 1/301 at MA of 18 years, and 1/9 at MA of 48 years. The proportion of clinically significant anomalies not addressed by current screening methods is 47% at MA of 18 years and 5% at MA of 48 years.
  
  
  CONCLUSIONS
  By determining frequencies for individual karyotype anomalies stratified by MA and GA, in the setting of normal-appearing fetuses, a more personalized risk assessment, including the residual risk after a normal fetal aneuploidy screening result, can be provided. © 2016 John Wiley & Sons, Ltd.
authors: 1st Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland.|Genomed S.A., Warsaw, Poland.
authors: Jose Carlos P
authors: http://orcid.org/0000-0003-0517-8230
authors: JC
authors: Ferreira
authors: Toma Advanced Biomedical Assays, Research and Development, Cytogenetics and Molecular Biology, Busto Arsizio, Varese, Italy.
authors: Francesca R
authors: FR
authors: Grati
authors: Albert Einstein College of Medicine, Bronx, NY, USA.
authors: Komal
authors: K
authors: Bajaj
authors: Toma Advanced Biomedical Assays, Research and Development, Cytogenetics and Molecular Biology, Busto Arsizio, Varese, Italy.
authors: Francesca
authors: F
authors: Malvestiti
authors: Toma Advanced Biomedical Assays, Research and Development, Cytogenetics and Molecular Biology, Busto Arsizio, Varese, Italy.
authors: Maria Beatrice
authors: MB
authors: Grimi
authors: Toma Advanced Biomedical Assays, Research and Development, Cytogenetics and Molecular Biology, Busto Arsizio, Varese, Italy.
authors: Anna
authors: A
authors: Trotta
authors: Toma Advanced Biomedical Assays, Research and Development, Cytogenetics and Molecular Biology, Busto Arsizio, Varese, Italy.
authors: Rosaria
authors: R
authors: Liuti
authors: Toma Advanced Biomedical Assays, Research and Development, Cytogenetics and Molecular Biology, Busto Arsizio, Varese, Italy.
authors: Silvia
authors: S
authors: Milani
authors: Toma Advanced Biomedical Assays, Research and Development, Cytogenetics and Molecular Biology, Busto Arsizio, Varese, Italy.
authors: Lara
authors: L
authors: Branca
authors: M.D. Candidate, Columbia University College of Physicians and Surgeons, New York, NY, USA.
authors: Jacob
authors: J
authors: Hartman
authors: Toma Advanced Biomedical Assays, Research and Development, Cytogenetics and Molecular Biology, Busto Arsizio, Varese, Italy.
authors: Federico
authors: F
authors: Maggi
authors: Toma Advanced Biomedical Assays, Research and Development, Cytogenetics and Molecular Biology, Busto Arsizio, Varese, Italy.
authors: Giuseppe
authors: G
authors: Simoni
authors: Albert Einstein College of Medicine, Bronx, NY, USA.
authors: Susan J
authors: SJ
authors: Gross
mesh_terms: D000293:Adolescent; D000328:Adult; D000649:Amniocentesis; D015193:Chorionic Villi Sampling; D025063:Chromosome Disorders / Q000453:epidemiology*; D004247:DNA / Q000032:analysis; D005260:Female; D005865:Gestational Age; D006801:Humans; D007621:Karyotyping; D016015:Logistic Models; D008423:Maternal Age; D008875:Middle Aged; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis; D018570:Risk Assessment; D016216:Ultrasonography, Prenatal; D055815:Young Adult
chemical_list: D004247:DNA