The document concludes that the high risk of infant, child, and maternal mortality is associated with pregnancies where mothers are too young, too old, or have already had several children.

该文件的结论是，婴儿、儿童和产妇死亡率高的风险与母亲年龄太小、太大或已经有几个孩子的怀孕有关。

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In other terms, pregnant women who gained 22.5 kilograms had double the risk of having an infant with a high birth weight compared with those who only gained about nine kilograms.

换言之，与体重仅增加9公斤相比，体重增加22.5公斤的孕妇所生婴儿体重高的风险加倍。

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High outdoor levels of nitrogen dioxide apparently raise the risk of sudden infant death syndrome (SIDS), according to California-based researchers.

美国加州大学的研究人员日前表示，户外高浓度的二氧化氮气会增加发生婴儿猝死综合症(SIDS)的危险。

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