This clinical trial is focused on studying the effects of a treatment for couples experiencing unexplained infertility. The treatment being tested is called Utrogestan, which is a soft vaginal capsule containing micronised progesterone. Progesterone is a hormone that plays a crucial role in the menstrual cycle and in maintaining the early stages of pregnancy. The study will also use a placebo, which is a capsule that looks like the real medication but does not contain the active ingredient, to compare the effects of the treatment.

The purpose of the study is to determine if adding progesterone support during a specific phase of the menstrual cycle, known as the luteal phase, can increase the chances of a live birth for couples undergoing a fertility treatment called intra-uterine insemination (IUI) with mild ovarian stimulation. This involves using a medication called FSH to gently stimulate the ovaries. The study will follow participants over a period of six months to observe outcomes such as pregnancy rates, live births, and any side effects experienced during the treatment.

Participants in the study will be monitored for various outcomes, including the number of IUI cycles they undergo, any pregnancies that occur, and the overall impact on their quality of life. The study will also assess the cost-effectiveness of adding progesterone support to the treatment. The findings from this study aim to provide valuable insights into improving fertility treatment outcomes for couples facing unexplained infertility.