Prevalence of aneuploidy in pregnant women with high risk fetal screening in Sabzevar perinatal clinic, 2016-2019

Proper and accurate screening of congenital anomalies and genetic diseases reduces the birth of babies with disorders and it is necessary to evaluate the diagnostic accuracy of the tests. Therefore, this study was performed with aim to evaluate the prevalence of aneuploidy in pregnancies with high-risk results of fetal screening methods.

This cross-sectional (descriptive-analytic) study was performed on 1454 patients referred to perinatology clinic in Sabzevar. After obtaining demographic information, the prevalence of aneuploidy in high-risk pregnancies was recorded. Data were analyzed by SPSS (version 26) and Chi-square and Fisher's exact tests. P<0.05 was considered statistically significant.

Based on amniocentesis and CVS test results, it was found that 1369 patients (94.2%) had normal, 41 (2.8%) had trisomy 21, 25 (1.7%) had Turner-Kleinfelter, 11 (0.8%) had trisomy 18, 2 (0.1%) had Trisomy 13 and finally 6 (0.4%) had other cases. There was a significant relationship between high-risk pregnancy tests and the presence of anaploidy (P <0.05). This means that screening tests have been able to optimally identify cases of aneuploidy. Only this relationship between high-risk test for trisomy 13 and genetic results was not significant (P=0.43).

Although normal cases are high in high risk individuals, but if a disorder be observed in screening, amniocentesis and CVS should be performed because especially in increased NT and nasal bone hypoplasia and in cases with high risk of trisomy 21 and 18, more accurate tests should be performed to prevent the birth of children with genetic defects by early diagnosis.