Negative predictive value of the chorionic villous sampling (CVS) in diagnosis of thalassemia in genetic laboratory of Dastgheib Hospital, Shiraz, Iran, 2012.

BACKGROUND Chorionic Villous Sampling (CVS) is a diagnostic method for determining genetic disorders. The present study aimed to determine the negative predictive value of the CVS in the diagnosis of major thalassemia in genetic laboratory of Dastgheib Hospital, Shiraz, Iran. METHODS The present research was an evaluation diagnostic test conducted on 372 records of embryos examined through CVS in the genetic lab in 2010 and definitely diagnosed by electrophoresis after birth in 2012. The sensitivity and positive predictive value of the test were assessed for minor thalassemia. The negative predictive value and the specificity of this test were determined, as well. RESULTS A total of 3 embryos (0.8%) were aborted due to testing. In this study, the sensitivity and specificity were 94.8% and 80.4%, respectively. Also, the negative predictive values for diagnosis of major and minor thalassemia were 100% and 89.2%, respectively. No relationships were found between the gestational age and the test results. CONCLUSION The results of this study showed that CVS genetic testing in genetic laboratory of Dastgheib Hospital was valid and had a high diagnostic value. Thus, minor couples can undergo this test with relative safety in order to prevent major thalassemia.