Smoking is more harmful to pregnant women, smoking in early pregnancy may lead to embryonic sterilizations, miscarriages, malformations, etc. Smoking in middle and late pregnancy may lead to intrauterine distress or neonatal asphyxia and other serious consequences, so pregnant women should quit smoking to avoid adverse effects on the fetus.1, fetal malformations: cigarettes contain a large amount of nicotine, which affects the growth and development of the embryo and is likely to cause fetal developmental malformations, such as fetal entropion, cleft lip and palate, etc., and may even cause fetal sterilizations. Even may cause embryonic sterilizations; 2, miscarriage: nicotine and other harmful chemicals within the cigarette, through the blood circulation into the placenta, easy to cause miscarriage; 3, fetal intrauterine distress: smoking will form carbon monoxide, affecting the combination of red blood cells and oxygen, nicotine so that vascular constriction, reducing the amount of blood circulation in the placenta, leading to fetal hypoxia, resulting in fetal intrauterine distress or asphyxia in newborns. If you find that you are pregnant and have already smoked, you should quit smoking immediately and stay away from smoking places to avoid second-hand smoke. Go to the hospital in time for a comprehensive examination, observe the development of the fetus, and analyze whether the pregnancy can continue in light of the time of menopause, the duration of smoking, and the number of cigarettes smoked. If the pregnancy can continue, take folic acid in the first 3 months of pregnancy as prescribed by the doctor to prevent fetal developmental abnormalities, and strengthen the obstetric examination at the same time. If the fetus has abnormalities, it is recommended to terminate the pregnancy according to medical advice.