Brody J A, Grant M D, Frateschi L J, Miller S C, Zhang H
Department of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, 60612-7260, USA.
Age Ageing. 2000 Jan;29(1):75-8. doi: 10.1093/ageing/29.1.75.
Female life expectancy in developed countries has increased by 30 years in the twentieth century.
To determine if there has been an increase in reproductive longevity.
We analysed age-specific fertility data from birth statistics for the USA, Canada, Japan, France, Sweden, the UK and Australia.
Since 1940, birth rates for women aged 35 and over have declined. Among women aged 50 years and older, there has been no increase in births. Fertility rates in 1990 were 0.0 to 0.044 per 1000 women, with total numbers ranging from 0 to 60 births.
The fertile years have not been prolonged in the cohort of women whose life expectancy has increased so dramatically this century. This suggests that reproductive senescence is tightly controlled and not extended by factors that enhance female longevity. Other physiological mechanisms may also be fixed within narrow age limits.
在二十世纪，发达国家女性的预期寿命增加了30岁。
确定生殖寿命是否有所延长。
我们分析了美国、加拿大、日本、法国、瑞典、英国和澳大利亚出生统计数据中按年龄划分的生育率数据。
自1940年以来，35岁及以上女性的出生率有所下降。在50岁及以上的女性中，出生人数没有增加。1990年的生育率为每1000名女性0.0至0.044，出生总数从0至60例不等。
在本世纪预期寿命大幅增加的女性群体中，生育年限并未延长。这表明生殖衰老受到严格控制，不会因延长女性寿命的因素而延长。其他生理机制可能也固定在狭窄的年龄范围内。
