Diagnosis of Aneuploidies by amniocentesis in high risk cases of first trimester screening test

Document Type : Original Article

Authors

1 M.Sc. of Midwifery, School of Paramedics, Islamic Azad University, Bonab Branch, Bonab, Iran.

2 M.Sc. of Midwifery, Faculty of Medicine, Islamic Azad University, Tabriz Branch, Tabriz, Iran.

3 M.Sc. of Library and Information Science, School of Nursing and Midwifery, Tabriz University of Medical Sciences, Tabriz, Iran.

Abstract

Introduction: Early diagnosis of congenital abnormalities at early of pregnancy and termination of these pregnancies can prevent from birth of defective newborns that are overload for family and society. This study was performed with the aim to diagnose aneuploidies by amniocentesis in high risk cases identified by first trimester screening test.
Methods: This descriptive-analytic (cross-sectional) study was performed on 121 pregnant women that their result of Down syndrome and other Aneuploidy screening were high risk at first trimester of pregnancy (11 to 13 weeks and 6 days) and were referred to fetus medicine section of Tabriz Alzahra hospital to perform amniocentesis (15-20 weeks) in 2013. A questionnaire was used for data collection which includes demographic characteristics of the subjects, data obtained by the results of first trimester screening tests, and data obtained by amniocentesis (the results of fetus karyotype). Data was analyzed using SPSS software (version 13) and coefficient tests, T-Test, and ANOVA. P≤0.05 was considered significant.
Results: Aneuploidy was detected in 11 newborns that 5 Down syndrome, 3 cases of trisomy 18, and 1 Klinefelter's syndrome were identified. There were significant relationship between risk of Down syndrome and amniocentesis results (P= 0.0001) and between increasing NT thickness and amniocentesis results (P= 0.04). There was no significant relationship between demographic characteristics of the subjects and results of first trimester screening (P>0.05). There were significant relationship between age (P= 0.03), number of delivery (P= 0.047), number of alive children (P= 0.036) and history of anomaly in previous child (P= 0.001) and amniocentesis results.
Conclusion: In the present study, 10% of high risk cases identified by first trimester screening test were diagnosed as aneuploidy by amniocentesis.

Keywords


  1. Royal college of obstetricians and Gynecologists amniocentesis and chorionic villous sampling. Greetop guideline No. 8. June 2010.
  2. Nussbaum RL, McInnes RR, Willard HF.Thompson &Thompson Genetics in Medicine. 3st Ed.Philadelphia: W.B. Saunders Company. 3st Ed; 2001
  3. Eiben S, Glaubitz R. First trimester screening; an overview. J Histchem & Cytochem 2005; 53:1-3.
  4. The fetal medicine center [homepage on the internet. London: the center; C 2009]. Available from: http.//www Fetal medicine.com/FM
  5. Penrose Ls. The effects of change in maternal age distribution upon the medicine of mongolism. J Ment Defic Res 2009; 11(1); 54-7.
  6. Farndon PA, Kilby MD. Genetics, risks, and genetics counseling. In: James DK, Steer PJ, Weiner CP,Gonik B. High risk pregnancy. 3st Ed. Philadelphia: Elsevier Saunders; 2005; 43-63.
  7. Wild Schut, Weiner, Peters. When to screen in obstetrics and gynecology1 and 2. 1st Ed. Qom. Fanose Andishe pub; 2011.
  8. Cunningham F.G, Leveno K.J, Bloom S.L, Hauth J.C, Rouse D.J, Spong C.Y. Williams Obstetrics. 23st Ed. New York. McGraw Hill Co; 2010.
  9. Nicolaides KH: Nuchal translucency and other first-trimester sonographic markers of chromosomal abnormalities. Review article. Am J Obstet Gynecol 2004; 191:45.
  10. ACOG. practice bulletin, invasive prenatal testing for aneuploidy. abstet- gynecolo 2007;1459-67.
  11. Pourjavad M, Dadgar S. Shakeri MT, Mahmodi M. Evalunation of triple test results and determining the median of serum markers for diagnosis of first –trimester congenital anomalies. Iranian journal of Obstetrics, Gynecology and Infertility 2010; 13(1), 21-26. [Article in Persian]
  12. Kagan KO, Wright D, Baker A, Sahota D, Nicolaides KH. Screening for trisomy 21 by maternal age, fetal nuchal translucency thickness, free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A. Ultrasound Obstet Gynecol 2008; 31(6):618-24.
  13. Chih-Ping Chen, Chen-Ju Lin, Wayseen Wang. College of Chinese Medicine, China Medical University, Taichung, Taiwan.Impact of second-trimester maternal serum screening on prenatal diagnosis of down syndrome and the use of amniocentesis in the Taiwanese population. Taiwanese J Obstet Gynecol , 2005; 44(1):31–35.
  14. Shahshahan Z, Azami N. The Diagnostic Value of Combined Test for Trisomy 21 and 18 screening in over 35-years Old Pregnant Women in the Gestational Age of 9-14 weeks. Journal of Isfahan Medical School 2013; 31(231):400-407. [Article in Persian]