1, may be a woman taking medication for abortion after vomiting, so the dose of medication is low, it will not fall off. 2, if a woman is pregnant with a large gestational sac, the diameter of more than 2 centimeters or a woman’s cervical opening is too tight, so that the gestational sac is not able to be discharged through the cervical opening. 3, a woman in the uterine cavity adhesion or uterine fibroids and so on, which affects the gestational sac to be discharged, it can also lead to fall off. 4, when a woman is more than 40 years old, it may also lead to fall off. When a woman is over 40 years of age, she may not be able to fall out either. When a woman takes medication for abortion, the chance of complete abortion is around 90%, and if it is not able to flow out in time, it is necessary to give timely clearance treatment. Therefore, when women take medication for abortion, they need to strictly follow the precautions for taking it, and it must be carried out in a hospital that has emergency measures to clear the uterus.