ABSTRACT
Objective: The present study aimed at evaluating and improving the knowledge regarding prenatal test indications by assessing the results of the invasive prenatal tests for the detection of fetal chromosomal anomalies conducted in our tertiary center. Material and Methods: A retrospective study was conducted to collect the results of prenatal invasive procedures performed in our tertiary center between January 2002-September 2017. The types and prevalence of fetal chromosomal anomalies were identified and the efficiency of the invasive procedure indications in predicting these fetal chromosomal anomalies was investigated. Results: The results of 2136 invasive procedures (2014 amniocentesis, 80 cordocentesis, and 42 chorion villus samplings) revealed 101 (4.72%) fetal chromosomal anomalies and 128 (5.99%) chromosomal polymorphisms. The most common chromosomal anomaly observed was trisomy 21 (n=52), followed by trisomy 18 (n=12). In terms of diagnosis of the fetal chromosomal anomalies, the following observations were made: the indication "major structural anomaly in the ultrasound (USG)" exhibited 31.68% sensitivity and 82.03% specificity with an odds ratio (OR) of 2.11 (95% CI: 1.37-3.27); the indication "screening test positivity" exhibited 44.55% sensitivity and 48.25% specificity [OR=0.75 (95% CI: 0.50-1.13)]; and the co-existence of "major structural anomaly in the USG" and "screening test positivity" exhibited 8.91% sensitivity and 98.24% specificity [OR=5.49 (95% CI: 2.54-11.84)]. Conclusion: Fetal chromosomal anomaly rate was observed to be 4.72%. The co-existence of a sonographic major fetal structural anomaly and serum screening test positivity was observed to maximize the risk of numerical as well as a structural chromosomal anomaly. The data from the present study which reflected screening performances of detailed USG and biochemical screening tests for the detection of fetal chromosomal anomalies may be useful for clinicians while performing detailed counseling of patients.