Results Results from chromosome selective sequencing were available from 253 cases of 255 cases. In two cases fetal cell fraction was below the minimal requirement of 4%. In this population of 255 cases we found euploid pregnancies in 250 cases and 5 aneuploid pregnancies: two trisomies 21, one trisomy 18, one triosmy 13 and one 45 XO. In 195 pregnant women, the performance of screening by comb...

The performance of prenatal screening tests for the identification of trisomy 21 (Down syndrome) has markedly improved since the 1970s and early 1980s when maternal age was the sole mode of screening the general pregnant population. With the discovery of second trimester serum markers in the 1980s and 1990s and implementation of double, triple, and quad marker testing; the discovery of first tr...

Background In singleton pregnancies, studies investigating cell-free DNA in maternal blood have consistently reported high detection rate and low false-positive for the 3 common fetal trisomies (trisomies 21, 18, 13). The potential advantages of noninvasive prenatal testing twin pregnancies are even greater than singletons, particular lower need invasive consequent loss rate. However, several o...

Prenatal screening is often misconstrued by patients as screening for trisomy 21 alone; however, other chromosomal anomalies are often detected. This study aimed to systematically review the literature and use diagnostic meta-analysis to derive pooled detection and false positive rates for aneuploidies other than trisomy 21 with different prenatal screening tests. Non-invasive prenatal testing ...