OBJECTIVES. Infertility affects at least 2 million couples in the United States. One third of infertility is attributed to male causes, but the etiology of most male infertility remains obscure. This study was designed to investigate the relationship between Chlamydia trachomatis and unexplained infertility in men. METHODS. Questionnaires and serum were collected prospectively from 52 case subjects (men from couples with explicitly defined idiopathic infertility) and 79 control subjects (first-time expectant fathers). RESULTS. Case subjects were significantly more likely than control subjects to be seropositive for antibody to C trachomatis at a titer of 1:64 or higher. By test of trend, higher titers were associated with higher odds ratios. Adjustment for age of either partner at initiation of pregnancy attempt, race, income, previous genitourinary symptoms or diagnoses, number of previous sexual partners, and barrier contraceptive use had no significant effect on the estimate of the odds ratio. One half of the men who were antibody positive had no history of genitourinary symptoms. CONCLUSIONS. Our results suggest an association between infection with C trachomatis in men and unexplained infertility and imply that infection is frequently asymptomatic.

Objective Prior studies describing menses duration and heaviness of flow during the menopausal transition (MT) have been short in duration and limited to white women. We estimated the frequency of and risk factors for prolonged bleeding, spotting, and heavy bleeding during the MT in an ethnically diverse population. Design Prospective community–based cohort study. Setting United States: Southeastern Michigan, Northern California, and Los Angeles, California. Population 1320 midlife women who participated in the Study of Women’s Health Across the Nation (SWAN) Menstrual Calendar Substudy. Participants included African-American, white, Chinese, and Japanese women. Methods Women completed daily menstrual calendars from 1996–2006, and provided information on hormone therapy, smoking and physical activity. Annual measures included height and weight. Kaplan-Meier survival analysis and multivariable regression were used to analyze the data. Main Outcome Measures Menses of 10+ days, spotting of 6+ days, heavy bleeding of 3+ days. Results At least three occurrences of menses 10+ days was reported by 77.7% (95%CI: 56.7, 93.2), of 6+ days of spotting by 66.8% (95%CI: 55.2, 78.0) and of 3+ days of heavy bleeding by 34.5% (95%CI: 30.2, 39.2) of women. Menses of 10+ days, 6+ days of spotting, and 3+ days of heavy bleeding were associated with MT stage, uterine fibroids, hormone use, and ethnicity. BMI was associated with 3+ days of heavy bleeding. Conclusions These data provide clinicians and women with important information about the expected frequency of prolonged and heavy bleeding and spotting during the menopausal transition that may facilitate clinical decision making.