The best blood sugar range for pregnant women is 5.3 mmol/L or less if they are fasting, and usually under 5.1 mmol/L is normal. Blood sugar level is very important during pregnancy, if it is high it can cause hyperglycemia during pregnancy, if it is low it can cause dizziness and even affect fetal development. If a pregnant woman suffers from low blood sugar during pregnancy, she can eat foods that can raise blood sugar, such as grapefruit, blueberries and so on. If you have high blood sugar during pregnancy, you should reduce the intake of foods high in sugar and eat less sweet foods in general. This is because high blood sugar during pregnancy may cause gestational diabetes, which is not good for the pregnant woman and the fetus.