The pregnancy rates of cohorts of idiopathic infertility couples gives insights into the underlying mechanism of infertility.

OBJECTIVES: To determine causes of "idiopathic" infertility, the IVF-ET experience of three cohorts of couples with this diagnosis was examined. DESIGN: Three cohorts of idiopathic infertility couples undergoing IVF-ET: a "failed IUI" group, three previous controlled ovarian hyperstimulation (COH)-IUI cycles with no pregnancies; a "conversion" group, patients converted during a COH-IUI cycle to IVF-ET because of excess follicle numbers; and a "direct IVF" group, patients proceeding directly to IVF-ET were compared. SETTING: A tertiary referral reproductive medicine unit. PARTICIPANTS: Forty-one idiopathic infertility couples. INTERVENTION: In vitro fertilization-ET. MAIN OUTCOME MEASURES: Number of oocytes retrieved, percent oocytes fertilized, number embryos per ET, implantation rate, percent pregnancy per cycle. RESULTS: The cohorts had similar fertilization rates and mean (+/- SD) number of pre-embryos transferred. The conversion group demonstrated a higher pregnancy rate (PR) per cycle and a higher E2 concentration than the other groups. The PR of 35.0% in the direct IVF group appeared higher than the 16.7% rate observed in the failed IUI group. CONCLUSIONS: Our observation of a lower PR in couples in the failed IUI group (16.7%) than in couples in the direct IVF group (35.0%) suggests pre-embryo developmental problems or implantation problems as likely important etiologies for a large proportion of idiopathic infertility couples. However, as the conversion group demonstrated both a significantly higher E2 concentration ([E2]) and per cycle PR than the other cohorts with similar fertilization and pre-embryo transfer rates. Subjects converted in a COH-IUI cycle to IVF-ET are thus either more likely to produce pre-embryos more genetically capable of continued development to implantation stage (i.e., better oocytes recruited and fertilized) or due to the higher [E2] to have endometrium more receptive to implantation. Neither undiagnosed tubal factors nor fertilization problems appear to be major etiologic contributors.

Mandibular subluxation for high carotid exposure.

Twenty-four patients with internal carotid artery lesions extending above the second cervical vertebra underwent mandibular subluxation for additional exposure. The original technique of bilateral arch bar wiring requiring 90 minutes for application has evolved into a circummandibular/transnasal wiring technique requiring approximately 10 minutes. Subluxation of the mandibular condyle 10 to 15 mm anteriorly results in displacement of the mandibular ramus 20 to 30 mm anteriorly. This technique provides a marked increase in exposure of the internal carotid artery up to the base of the skull by transforming a triangular operating field into a rectangular field. The technique is quick, easy to perform, and not associated with objective or subjective temporomandibular joint dysfunction.