Abstract

Background: Multiple studies have demonstrated SneakPeek® Early Gender Test’s ability to accurately determine fetal sex as early as 8 weeks gestation with greater than 99% accuracy. The qPCR-based assay was further optimized to determine fetal sex at 7 weeks gestation. The objective of this study was to evaluate SneakPeek’s clinical performance for noninvasive prenatal testing (NIPT) to determine fetal sex as early as 7 weeks gestation.
Method: A multicenter non-randomized, controlled study was carried out at twelve healthcare clinics in the United States to assess the performance of the SneakPeek Early Gender Test for fetal sex identification at 7 weeks gestational age. In this study, 134 pregnant women consented to two blood draws: one draw at 7 weeks gestation and a second draw between 8- and 10-weeks’ gestation. Plasma was separated from whole blood samples by centrifugation. Circulating cell-free DNA was isolated from maternal plasma using a DNA isolation kit for the 7- and 8
to 10-week gestation samples. After extracting the cell-free DNA from these samples, real-time quantitative PCR was used to detect fetal DNA using a multi-copy sequence on the Y chromosome. Maternal and fetal circulating free DNA (total cell-free DNA) was measured using an autosomal control gene. Test results from the 8 to 10-week gestation blood samples were used to confirm the 7-week test results.
Results: Male Y-chromosome was detected in all samples from participants carrying a male fetus. Inconclusive results were obtained for 3 pregnancies. SneakPeek correctly identified fetal sex in the remaining 131 pregnancies at 7 weeks gestation. Fetal sex status for all samples was unknown prior to genetic testing. Since SneakPeek® Early Gender Test was previously shown to be 99.9% accurate at 8 weeks or later gestation, the results for 7 week gestation samples were confirmed with the 8 to 10-week sample results. In this study, SneakPeek accuracy was 100% for fetal
sex identification at 7 weeks gestation.
Conclusion: This study demonstrated that SneakPeek® Early Gender Test is highly accurate for fetal sex determination in pregnancy as early as 7 weeks gestation.

Keywords: 7 weeks gender blood test; SneakPeek accuracy; Gender blood test; SneakPeek; Gender test