If you need to promote ovulation, you can take HCG shots during ovulation. When a follicle does not ovulate with HCG, or human chorionic gonadotropin, ovulation usually occurs in about 36 hours. The factors that cause female infertility are the existence of abnormal ovulation, and the fallopian tube is open, the uterine lining is also good, can be injected with HCG to help ovulation, before and after the ovulation of coitus will increase the chances of pregnancy. If a woman also has tubal failure, she can have her eggs retrieved artificially. In the retrieval of eggs can be obtained more than one egg, and then with the sperm combination in vitro to raise sacs successfully after the development of a certain stage of the blastocysts will be transplanted to the uterine cavity to implant, growth and development, in order to help improve the success rate of IVF. HCG can only be used when the follicles have developed to a certain level. As it is a hormonal drug, the right dosage must be injected under the guidance of a doctor and within a specified time frame before it can work.