Unexplained infertility

Abstract

Unexplained infertility diagnosis is made in the presence of a normal semen analysis when tubal patency and normal ovulatory function are established. Among several potential causes, unexplained infertility could be attributed to vaginal pH and cervical mucus abnormalities. Although the vaginal canal and the cervix generally function as effective barriers to sperm, and although the production of mucus is essential to transport them from the vagina to the uterine cavity, these factors receive little attention in the investigation of couples with unexplained infertility. A substantial reduction in sperm number occurs as they transverse the cervix. From an average of 200 to 300 million sperm deposited in the vagina, only a few hundred achieve proximity to the oocyte. Given this expected high spermatozoa loss, a slight modification in cervical mucus may rapidly transform the cervix into a "hostile" environment, which, together with changes in vaginal environment and cervix structure, may prevent natural conception and be a cause of infertility. In this review, we discuss the physiological role of the vaginal pH and cervical mucus in fertility, and describe several conditions that can render the cervical mucus hostile to sperm and therefore be implicated in the pathophysiology of unexplained infertility.

Clomiphene Citrate for Women with Unexplained Infertility

“…The European Society of Human Reproduction and Endocrinology (ESHRE) workshop concluded that ovarian stimulation with CC doubled the pregnancy rate in women with unexplained infertility [65]. An analysis by the Practice Committee of the American Society of Reproductive Medicine in 1998 of the effectiveness of different empiric regimens for unexplained infertility reported in 45 studies found the clinical pregnancy rate per cycle to be 5.6 % for CC alone and 8.3 % for CC-IUI compared to 1.3-3.4 % for no treatment [3].…”

Follow-Up of Patients with Unexplained Infertility Who Previously Underwent Natural Cycle in vitro Fertilization

“…There may be two possibilities: (1) there is a real similarity in implantation in both treatment groups, or (2) there is a difference in implantations in both treatment groups, again not shown because of the lack of reaching the numbers needed.…”

“…A dose of hMG (150 IU) was given IM each day but could be individually adjusted to the ovarian response until at least 3 follicles 1 16 mm were achieved with approximately 1,000 pmol/l plasma E 2 for each follicle. Provided there was no excessive ovarian stimulation (plasma E 2 concentration 1 14,000 pmol/l), hCG (10,000 IU) was given IM and egg recovery by ultrasound (Combison 310, Kertztechnik, AG, Austria) guided needle aspiration transvaginally planned [1] 34-36 h afterwards. The retrieved eggs were handed to the embryologists to inseminate with prepared husband's semen and their development and cleavage monitored.…”

“…Published data suggest that there is no benefit in using danazol or bromocriptine in unexplained infertility [1]. The empirical use of clomiphene citrate has been evaluated [2][3][4].…”

Fimbrio-Ovarian Relationship in Unexplained Infertility

“…It is estimated that the incidence of infertility is 17% in the world and in 10% of these couples, the cause is not known [1,2] . There have been many postulates to explain…”