Conclusions
Continuous detection of a significant risk of fetal trisomy after fetal
reduction indicated that residual cfDNA remained in maternal plasma for
around 12 to 22 weeks after fetal demise. The persistent detection of
residual cfDNA of the demised co-twin has a long-lasting influence on
the results of NIPT. It should be cautious about providing NIPT in
pregnancies with a risk of fetal demise.