He says the best time to take folic acid to reduce the risk of autism seems to be from four weeks before to eight weeks after the start of pregnancy. The researchers found that taking folic acid halfway through pregnancy had no effect.他表示,服用叶酸以降低自闭症风险的最佳时机似乎是怀孕前四周到怀孕后八周.研究人员发现,在怀孕中期服用叶酸并无效果.
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