Smoking causes Women who smoke during pregnancy and the baby will have a birth weight of infants less than normal. In addition, smoking also increases the risk of complications in pregnancy, such as placenta previa, placental abruption. Premature Babies The risk of miscarriage increases two times or if they are not pregnant. Women also face infertility and so on. The unborn child was born, a little weight. Development Incomplete Because of the slow growth in the womb Have died at birth is much higher. Because the toxicity of smoking can be transmitted from the mother's bloodstream through the placenta to the baby directly, if children are breastfed. Children will have the chance of infection in the respiratory tract and ear infections more often. There is a chance of asthma and allergies more clearly.