The intake of folic acid before pregnancy is more necessary, generally at least 3 months before pregnancy, the details are as follows: 1. women who have given birth to a fetus with neural tube abnormality: it is recommended to intake folic acid before pregnancy until 3 months of pregnancy; 2. women who have not taken folic acid: if the preparation time is urgent, such as a preconception test last month and prepare for pregnancy next month, for such women who have not taken folic acid supplementation, it is recommended to take folic acid supplementation for at least 1 month before pregnancy; 3. women who have prepared adequately for pregnancy: if the preparation time is more than 3 months, it is recommended to take folic acid supplementation until 3 months of pregnancy.