[The value of re-sampling for patients who had failed non-invasive prenatal testing due to low cell-free fetal DNA fraction].

ABSTRACT

OBJECTIVE: To assess the value of re-sampling for patients who had failed non-invasive prenatal testing (NIPT) due to low cell-free fetal DNA (cffDNA) fraction. METHODS: Clinical data of 20 387 patients undergoing NIPT test was reviewed. The patients were re-sampled when initial blood test did not yield a result due to cffDNA fraction. The results were analyzed, and the outcome of pregnancy was followed up. RESULTS: Among all samples, 17 (0.08%) had failed to yield a result due to low cffDNA fraction, all of which accepted re-sampling. A result was attained in 16 cases, with a success rate of 94.12%. Only one sample had failed the re-test. CONCLUSION: For patients who had failed the initial NIPT due to low cffDNA fraction, re-sampling should be considered with gestational week and ultrasound results taken into consideration.