雅思阅读：双胞胎的母亲更长寿

一项的研究发现，育有双胞胎的母亲寿命较长。当然这倒不是说每天多洗一堆尿布能使人长寿，而是能生双胞胎的妇女首先身体就不会差。

　　Having two babies at a time is associated with a longer life, according to a new study. But that''s not because doubling up on dirty diapers increases life span; instead, moms of twins are physically stronger in the first place。

　　The research, published in the journal Proceedings of the Royal Society B, focused on a "natural fertility" population of women in 1800s Utah, so the results may not apply in today''s in vitro fertilization (IVF) world。

　　The research team used the Utah Population Database, an enormous genealogical record of Utah residents dating back to the early 1800s. From the database, they pulled family records of women who were born between 1807 and 1899 and who lived to be at least 50, so they experienced their full range of reproductive years。

　　They excluded widows and wives in polygamous families to ensure they were comparing similar women。

　　The result was a database of 58,786 women, 4,603 of whom had at least one set of twins。

　　The researchers compared the moms of twins with the moms of singletons, looking for differences in life span, number of children, time between pregnancies and length of fertility, all measures of health。

　　The researchers found that moms of twins beat moms of only singletons on every measure. They lived longer, had longer reproductive life spans, needed less time to recover between pregnancies, and had more children overall。

　　一项的研究发现，育有双胞胎的母亲寿命较长。当然这倒不是说每天多洗一堆尿布能使人长寿，而是能生双胞胎的妇女首先身体就不会差。

　　刊登在英国《皇家学会学报B刊》的这篇文章以19世纪美国犹他州"自然受孕"的妇女为研究的主体，所以它的研究成果在现代这个体外受精盛行的社会或许并不太适用。

　　研究小组查阅了犹他州居民信息数据库，该数据库储存的信息较早可追溯到19世纪初期。研究人员从数据库中挑选出生于1807年至1899年间，且寿命不低于50岁的妇女的家庭信息，以便掌握她们的详细情况。

　　他们没有采用丧偶或有一夫多妻家庭背景的妇女的信息，以他们研究的是同一个人。

　　在符合条件的58786名妇女当中，研究人员发现有4603名妇女至少生过一次双胞胎。

　　接下来研究人员将这些妇女的各项数据进行了对比，比如寿命、有几个宝贝、每次怀孕间隔多久、育龄时间持续多久，这些都是衡量健康水平的指标。

　　经对比研究人员发现，比起仅有一个宝贝的母亲，双胞胎的母亲各项指标都要占优。她们寿命更长，育龄时间更久，产后恢复时间更短，当然宝贝也更多。