Association of lifetime lactation and characteristics of menopause: a longitudinal cohort study
The researchers used survey data on 19,783 parous women aged 40 to 65 years at enrollment in the Alberta’s Tomorrow Project to investigate the association between lifetime duration of lactation and the timing and type of menopause in midlife women. They found that in a dose-response manner, longer lactation was associated with reduced risk of natural menopause before age 50, surgical menopause before age 55, and indeterminate menopause before age 50. Longer lactation was associated with lower odds of surgical and indeterminate menopause, compared to natural menopause.
Unilateral Oophorectomy and Age at Natural Menopause: A Longitudinal Community-Based Cohort Study.
The researchers investigated the impact of unilateral oophorectomy (UO) on the age of natural menopause using data from Alberta’s Tomorrow Project. They found that UO was linked to an earlier age at natural menopause, with the strongest effect seen in women who had UO between ages 20-40. These findings highlight that UO, particularly before the age of 40, increases the risk of earlier natural menopause.
Education level is associated with the occurrence and timing of hysterectomy: A cohort study of Canadian women
The researchers used data of 30 496 females in the Alberta’s Tomorrow Project to determine the association between level of educational attainment and the occurrence and timing of hysterectomy in Canadian women. They found that women with lower levels of education were more likely to experience hysterectomy, including hysterectomy before menopause and at younger ages.
Association of parity with the timing and type of menopause: A longitudinal cohort study
The study aimed to determine the time-varying association between parity and timing of natural menopause, surgical menopause, and premenopausal hysterectomy among 23,728 women aged 40-65 years at enrollment in the Alberta’s Tomorrow Project cohort study. The researchers found that overall, natural menopause was most common, then premenopausal hysterectomy and surgical menopause. The risk of natural menopause before age 50 was higher for women with 0 or 1 birth, while the risk was similar for those with 3 or more births compared to those with 2 births. Elevated risks of surgical menopause before age 45 for women with 0 or 1 birth were reduced after excluding those with a history of infertility or recurrent pregnancy loss, and the risk decreased over time for women with 3 or more births. Additionally, the risk of premenopausal hysterectomy before age 50 was lower for women with 0 births but increased after age 40 for those with 3 or more births.