Temporal persistence of residual fetal cell-free DNA from a deceased cotwin after selective fetal reduction in dichorionic diamniotic twin pregnancies.

Residual cfDNA from the deceased cotwin after selective reduction at 14-17 gestational weeks led to the persistent generation of false-positive NIPT results for up to 16 weeks postdemise. Thus, providing NIPT for pregnancies with a cotwin demise in early second trimester is prone to misleading results and not recommended.