The endometrium is thickened in most patients with ectopic pregnancy, mainly because the gestational sac is also active in patients with ectopic pregnancy, so the patient’s estrogen and progesterone levels will be elevated, and the endometrium will appear to be thickened with the support of high hormone levels. Therefore, when the patient has an ultrasound, it will indicate that the endometrium is thickened, but the presence of the gestational sac cannot be seen, and instead, ectopic masses are found outside the uterine cavity. If the patient is ectopic pregnancy, but the activity of the gestational sac is not high, or the gestational sac gradually died, then the patient’s estrogen level will be lower, or the hormone level increases and then decreases, so that the endometrium does not have high hormone levels of support, and a small amount of exfoliation of the bleeding, in this case, the ultrasound will indicate that the endometrium is thin. So the thickness of the endometrium in patients with ectopic pregnancy depends on the activity of the ectopic gestational sac.