Tubal Ligation and Age at Natural Menopause.

<bold>Objective: </bold>To determine the effect of tubal ligation on age at natural menopause, as a marker of long-term ovarian function.<bold>Methods: </bold>Three preexisting population-based cohorts were included in this cross-sectional study. Data from each cohort was analyzed separately. The cohorts were restricted to women who never smoked and had reached natural menopause, without prior hysterectomy or oophorectomy. The following variables were collected: race, age at menarche, age at menopause, history of hysterectomy or oophorectomy, gravidity and parity, tobacco use, and ever use of hormonal contraception. The type of tubal ligation and age at tubal ligation were manually abstracted in cohort 1. For cohorts 2 and 3, history of tubal ligation was obtained from an institutional form, completed by patient report. The primary outcome, age at natural menopause, was compared between the two groups (those with and without a history of tubal ligation).<bold>Results: </bold>Inclusion criteria was met by 555 women from cohort 1, 1,816 women from cohort 2, and 1,534 women from cohort 3. Baseline characteristics did not differ between cohorts. The percentage with tubal ligation was the same in all cohorts: 26.0%, 25.5%, and 25.0%, respectively. Women with a tubal ligation were more likely to have had at least one pregnancy and to have used hormonal contraception compared with women without a tubal ligation. There was no significant difference in age at natural menopause in women who underwent tubal ligation (50.1, 49.9, 50.0 years, respectively) compared with those who did not (50.7, 49.6, 50.0 years, respectively). The type of tubal ligation (cohort 1 only) had no effect on age at menopause.<bold>Conclusions: </bold>Tubal ligation did not affect age at natural menopause in the three large cohorts included in this study. [ABSTRACT FROM AUTHOR]