COH: controlled ovarian hyperstimulation;
unLM: group of late miscarriage for unexplained factor;
feLM: group of late miscarriage for fetal factor;
ceLM: group of late miscarriage for cervical factor;
trLM: group of late miscarriage for trauma factor.
P1: unLM vs. Control, P2: feLM vs. Control, P3: ceLM vs. Control, P4:
trLM vs. Control.