Study of prenatal screening tests in pregnant women and comparison with fetal karyotype results

Document Type : Original Article

Authors

1 PhD student of Molecular Medicine, Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran, Physician, Isfahan Health Assurance, Isfahan, Iran.

2 MSc in Genetic, Medical Genetic Laboratory, Al-Zahra Medial and Educational Center, Isfahan University of Medical Sciences, Isfahan, Iran

3 Professor, Department of Genetics, Faculty of Medicine and Genetics Laboratory, Al-Zahra Medial and Educational Center, Isfahan University of Medical Sciences, Isfahan, Iran

4 BC student of Genetics, Department of Genetics, Falavarjan branch, Islamic Azad University, Isfahan, Iran

5 Assistant professor, Department of Obstetrics and Gynecology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

6 Physician, Department of genetics, Diseases Control Center, Ministry of Health and Medical Education, Tehran, Iran

7 Professor, Department of Biology, School of Sciences, Isfahan University, Isfahan, Iran

8 Physician, Isfahan Health Assurance, Isfahan, Iran

9 MSc in Genetic, Medical Genetic Laboratory, Al-Zahra Medial and Educational Center, Isfahan University of Medical Sciences, Isfahan, Iran PhD student of Medical Genetics, Faculty of Medicine, International branch, Tehran University of Medical Sciences, Tehran, Iran.

Abstract

Introduction:Regarding to the high prevalence of Down syndrome (1 per 700 births) different prenatal screening methods have been developed to identify high risk pregnant women. If the screening results were positive, prenatal genetic tests are recommended. This study was performed with aim to evaluate screening tests and comparison with fetal karyotype results.
Methods: In this cross-sectional, descriptive and analytical study, the results of screening tests and genetic tests of 1009 pregnant women who underwent aneuploidy screening test in the years2015-2016, was examined. The information includes demographic data, familial history of previous child affected with Down syndrome, consanguineous marriage was obtained and then the results of screening and genetic test were recorded in a designed questionnaire. Data were analyzed using SPSS software (version 19), P value less than 0.05 was considered significant.
Results: Based on the results of genetic tests, 59 cases (6%) of the studied fetuses had aneuploidy that 41 cases had Down syndrome. There was a significant relationship between screening tests and aneuploidy (P<0.05), but there was no significant association between the risk of neural tube defect (NTD) and aneuploidy (p>0.05). Also, significant relationship was found between NT>3mm and aneuploidy (P<0.001). The sensitivity and specificity of NT test to aneuploidy detection obtained as 47% and 90%, respectively.
Conclusion: Fetal screening tests can help in finding pregnant women at risk for a child with chromosomal abnormalities. Further studies are recommended to determine the sensitivity of screening tests.

Keywords


  1. Bringman JJ. Invasive prenatal genetic testing: a Catholic healthcare provider's perspective. Linacre Q 2014; 81(4):302-13.
  2. Milunsky A, Milunsky JM. Genetic disorders and the fetus: diagnosis, prevention, and treatment. New Jersey: John Wiley & Sons; 2015.
  3. Driscoll DA, Gross S. Prenatal screening for aneuploidy. N Engl J Med 2009; 360(24):2556-62.
  4. Gregg AR, Gross SJ, Best RG, Monaghan KG, Bajaj K, Skotko BG, et al. ACMG statement on noninvasive prenatal screening for fetal aneuploidy. Genet Med 2013; 15(5):395-8.
  5. Allen EG, Freeman SB, Druschel C, Hobbs CA, O’Leary LA, Romitti PA, et al. Maternal age and risk for trisomy 21 assessed by the origin of chromosome nondisjunction: a report from the Atlanta and National Down Syndrome Projects. Hum Genet 2009; 125(1):41-52.
  6. Malone FD, Canick JA, Ball RH, Nyberg DA, Comstock CH, Bukowski R, et al. First-trimester or second-trimester screening, or both, for Down's syndrome. N Engl J Med 2005; 353(19):2001-11.
  7. Nicolaides KH, Syngelaki A, Ashoor G, Birdir C, Touzet G. Noninvasive prenatal testing for fetal trisomies in a routinely screened first-trimester population. Am J Obstet Gynecol 2012; 207(5):374.e1-6.
  8. Summers AM, Langlois S, Wyatt P, Douglas Wilson R, Allen V, Blight C, et al. Prenatal screening for fetal aneuploidy. J Obstet Gynaecol Canada 2007; 29(2):146-61.
  9. Benn PA, Campbell WA, Zelop CM, Ingardia C, Egan JF. Stepwise sequential screening for fetal aneuploidy. Am J Obstet Gynecol 2007; 197(3):312.e1-5.
  10. Natoli JL, Ackerman DL, McDermott S, Edwards JG. Prenatal diagnosis of Down syndrome: a systematic review of termination rates (1995–2011). Prenat Diagn 2012; 32(2):142-53.
  11. Rezayat AA, Nazarabadi MH, Andalibi MS, Ardabili HM, Shokri M, Mirzaie S, et al. Down syndrome and consanguinity. J Res Med Sci 2013; 18(11):995-8. (Persian).
  12. Rittler M, Liascovich R, Lópezā€Camelo J, Castilla EE. Parental consanguinity in specific types of congenital anomalies. Am J Med Genet 2001; 102(1):36-43.
  13. Peuhkurinen S, Laitinen P, Honkasalo T, Ryynanen M, Marttala J. Comparison of combined, biochemical and nuchaltranslucency screening for Down syndrome in first trimester in Northern Finland. Acta Obstet Gynecol Scand 2013; 92(7):769-74.
  14. Cuckle H, Benn P, Wright D. Down syndrome screening in the first and/or second trimester: modelpredicted performance using meta-analysis parameters. Semin Perinatol 2005; 29(4):252-7.
  15. Genetics office, ministry of health. Iran University of Medical Sciences. Available at: URL: www.vct.iums.ac.ir/uploads/gharbalgari.syndrom.d.95html; 2015.
  16. Boyd PA, DeVigan C, Khoshnood B, Loane M, Garne E, Dolk H, et al. Survey of prenatal screening policies in Europe for structural malformations and chromosome anomalies, and their impact on detection and termination rates for neural tube defects and Down’s syndrome. BJOG 2008; 115(6):689-96.
  17. Hume RF Jr, Drugan A, Reichler A, Lampinen J, Martin LS, Johnson MP, et al. Aneuploidy among prenatally detected neural tube defects. Am J Med Genet 1996; 61(2):171-3.
  18. Ball RH, Caughey AB, Malone FD, Nyberg DA, Comstock CH, Saade GR, et al. First-and second-trimester evaluation of risk for Down syndrome. Obstet Gynecol 2007; 110(1):10-7.
  19. Reddy UM, Mennuti MT. Incorporating first-trimester Down syndrome studies into prenatal screening: executive summary of the National Institute of Child Health and Human Development workshop. Obstet Gynecol 2006; 107(1):167-73.
  20. Weiner Z, Goldstein I, Bombard A, Applewhite L, Itzkovits-Eldor J. Screening for structural fetal anomalies during the nuchal translucency ultrasound examination. Am J Obstet Gynecol 2007; 197(2):181.e1-5.
  21. Bahado-Singh RO, Wapner R, Thom E, Zachary J, Platt L, Mahoney MJ, et al. Elevated first-trimester nuchal translucency increases the risk of congenital heart defects. Am J Obstet Gynecol 2005; 192(5):1357-61.
  22. Odibo AO, Sehdev HM, Dunn L, McDonald R, Macones GA. The association between fetal nasal bone hypoplasia and aneuploidy. Obstet Gynecol 2004; 104(6):1229-33.
  23. Malone FD, Ball RH, Nyberg DA, Comstock CH, Saade G, Berkowitz RL, et al. First-trimester nasal bone evaluation for aneuploidy in the general population. Obstet Gynecol 2004; 104(6):1222-8.