It is well known that implantation of the developing blastocyst occurs during the luteal phase of the menstrual cycle when the endometrium is under the direct influence of Progesterone (P).Several prospective randomized controlled trials have evaluated the benefits of luteal phase P support in ovulation induction cycles and a recent review and meta-analysis demonstrated that it may be of benefit to patients undergoing ovulation induction with gonadotropins in intrauterine insemination (IUI) cycles. Until now, injectable P was offered only in an oil-base solution owing to the insoluble properties of the molecule, which made the IM route mandatory. A recent publication, however, demonstrated the efficacy of a new P formulation that could be a game changer. The aim of the present pilot trial will be to compare the efficacy and tolerability of 25 mg/d of the new SC P with 90 mg/d of vaginal gel P for luteal phase support (LPS) in COH and IUI cycles.

The present randomized study will be conducted to compare the safety, effectiveness and tolerability of SC P (Pleyris; IBSA Institut Biochimique SA) with vaginal P gel (Crinone; Merck Serono) for LPS in COH/IUI cycles. The study will be conducted, recorded and reported in compliance with the principles of Good Clinical Practice (GCP) guidelines at the Department of Obstetrics and Gynecology of Magna Graecia University of Catanzaro.

Inclusion Criteria:

<38 years of age with either primary or secondary infertility for at least 1 years; body mass index between 19 and 30 kg/m2; Day 2 serum FSH <15 IU/ml; normal serum prolactin level; normal uterine cavity on hysterosalpingography or hysteroscopy.-

Exclusion Criteria:

female partners with previous ovarian surgery, one ovary, polycystic ovaries on ultrasound examination, other endocrine abnormalities (i.e., polycystic ovarian syndrome, thyroid disorders, hyperprolactinemia, hypogonadotropic hypogonadism), diminished ovarian reserve (basal FSH level >15 IU/mL), or age of >38 years