Progesterone injection for 14 days when doing IVF, pregnancy or stop after another 7 days. Due to the need for down regulation, LH is lower after down regulation and low LH affects progesterone and luteinizing hormone function. Luteinizing support is required for egg retrieval to remove some granulosa cells and IVF fresh embryo cycle. There are various kinds of luteal support, such as injection, oral, and cathartic plug, and too much injection dose is easy to cause local redness, ulceration, rupture or abscess. Therefore, the injected dose is now less. Generally, after fresh embryo transfer, injections are given for 14 days and pregnancy or stopped after another 7 days. Test blood progesterone value, progesterone value is better and fetus development is better can be discontinued, after luteal conversion of 6-8 weeks for oral and Yin plug, 8-9 weeks for oral and Yin plug can be discontinued.