Background: Reproductive events are associated with important physiologic changes yet little is known about
how reproductive factors influence long term health in women. Our objective was to assess the relation of
reproductive characteristics with all-cause and cause-specific mortality risk.
Methods: The analysis was performed in the European Investigation into Cancer and Nutrition prospective
cohort study that enrolled >500,000 women and men (1992-2000) who were residing in a given
town/geographic area in 10 European countries. The current analysis included 322,972 eligible women aged 25-
70 years with 99% complete follow-up for vital status. We assessed reproductive characteristics reported at the
study baseline including parity, age at the first birth, breastfeeding, infertility, oral contraceptive use, age at
menarche and menopause, total ovulatory years and history of oophorectomy/hysterectomy. Hazard ratios
(HRs) and 95% confidence intervals (CIs) for mortality were determined using Cox proportional hazards
regression models adjusted for menopausal status, body mass index, physical activity, education level and
smoking status/intensity and duration.
Results: During a mean follow-up of 12.9 years, 14,383 deaths occurred. The HR (95% CI) for risk of all-cause
mortality was lower in parous versus nulliparous women, 0.80 (0.76-0.84), in women who had ever versus
never breastfed, 0.92 (0.87-0.97), in ever versus never users of oral contraceptives (among non-smokers), 0.90
(0.86-0.95), and in women reporting a later age at menarche (≥15 years versus <12), 0.90 (0.85-0.96), P for
trend=0.038.
Conclusions: Childbirth, breastfeeding, oral contraceptive use, and a later age at menarche were associated with
better health outcomes. These findings may contribute to the development of improved strategies to promote
better long term health in women.