新近医学界调查发现,在受孕前预先服用一种B族维生素叶酸一个月以上,胎儿出生缺陷的发生率可减少50%。神经管缺陷发生在妊娠早期,是胎儿死亡的主要原因。无脑儿和脊柱裂是最常见的出生缺陷,发生率在0.08～1%之间。无脑儿出生后即刻死亡,大部分脊柱裂婴儿存在不同程度的残废。由于怀这种神经管缺陷胎儿的母亲95%以前 Recent medical survey found that preconception before taking a B vitamins more than a month, the incidence of fetal birth defects can be reduced by 50%. Neural tube defects occur in early pregnancy and are the leading cause of fetal death. No brain children and spina bifida is the most common birth defects, the incidence rate of 0.08 to 1%. No brain children died immediately after birth, most of spina bifida babies have varying degrees of disability. 95% of pregnant mothers with this neural tube defect were pregnant