Specificity and Sensitivity of NIPT for Prenatal Screening of Down Syndrome in 100 Pregnant Women from Tonekabon, Iran

Abstract

Down syndrome is one of the most common genetic disorders, with a prevalence of one in 600 live births. There are numerous methods for diagnosis of this syndrome before birth such as non-invasive prenatal testing (NIPT). This test evaluates positive and negative predictive values of Down syndrome screening as well as determining the gender of the fetus. Data were collected from 100 pregnant women who visited obstetrics and gynecology clinic of Tonekabon Hospital, Tonekabon, Iran. The average age of pregnant women was 35.9 and the average gestational age was 12 to 13 weeks. About 40% of participating mothers had a history of previous pregnancies (32%), 45% of mothers had no history of live births and none of them had a family history of developing Down syndrome. According to the results, 56 percent of babies were male and 44 percent were female and none of the fetuses had Down syndrome. Results of the present study also indicated that NIPT sensitivity and specificity in the diagnosis of Down syndrome and also the baby's gender were 100%. The positive and negative predictive values were also 100% as well. This study has shown that NIPT as a diagnostic test is used to detect Down syndrome in all pregnancies, including high-risk pregnancies such as cases with high maternal age. Another important issue which has to be taken into account is a source of support such as Insurance coverage for the test.