Brown discharge 9-11 days after embryo transfer may be caused by pre-eclampsia, ectopic pregnancy and other reasons. 1. Pre-eclampsia: Embryo transfer refers to in vitro fertilization-embryo transfer technique, which is an artificial assisted reproduction technique and should be operated by a professional doctor. When there is brown discharge 9-11 days after the transfer, it may be the manifestation of pre-eclampsia, and may also be accompanied by pain in the lower abdomen, which can be diagnosed with the help of blood HCG (human chorionic gonadotropin) test and progesterone. 2. Ectopic pregnancy: It may also cause a small amount of brown vaginal discharge after implantation, and may be accompanied by pain in one side of the lower abdomen. Blood HCG level and progesterone test can be used to make preliminary diagnosis and dynamic observation of the clinical manifestations, and ultrasonography is usually carried out around 4 weeks after implantation to make a clear diagnosis. When there is brown discharge 9~11 days after embryo transfer, you need to go to the hospital in time to find out the cause and deal with it actively.