Hair straightening when the month pregnant on the embryo is not affected, because the fertilized egg needs a certain amount of time to bed, before bed the fertilized egg and the mother is not a common blood supply. If the exposure to toxic and harmful substances does not have much effect on the embryo, hair straightening itself does not have much effect on the body, some of the potions will be present in the body with harmful ingredients, the body absorption is also very little. You need to pay attention to regular prenatal checkups to understand the growth and development of the fetus, to avoid abnormal development, and to achieve eugenics. After pregnancy, you need to pay attention to more rest, strengthen the nutritional intake and diversify nutrition, which can effectively prevent the fetus from malnutrition, which can lead to abnormal development. Try to avoid exposure to toxic and harmful substances during pregnancy, especially in early pregnancy, to avoid affecting the development of the fetal nervous system.