I hope I can answer your question today. I performed a review of relevant medical literature to give you complete information. A CL or corpus luteum cyst, is a normal part of the ovary that makes pregnancy hormones during the first trimester of pregnancy. Sometimes the CL can rupture and disappear, or never be formed at all. The two main hormones that support pregnancy are HCG and progesterone. Progesterone is widely used to help prevent miscarriage in at-risk pregnancies. But HCG is more controversial and has not been proven yet to be effective. There is also no guarantee that the missing CL cyst will actually cause a miscarriage. There are many normal and successful pregnancies where the CL cyst is absent, and blood levels of HCG and progesterone in the mother do not correlate with the size or presence of a CL cyst. So the treatment recommended to you is controversial, and is not standard of care in the U.S. I would encourage you to seek a other opinions about this treatment. I hope my advice was helpful and best of luck to your wife and with your pregnancy.