Tetrafluoroethrin pyrethrin can not be used by pregnant women, is to have an effect on pregnant women. Tetrafluoromethyl ether pyrethrin has a certain toxic effect, is the active ingredient in mosquito coils, mosquito coils in trace amounts of anesthetic or poison used to anesthetize or poison mosquitoes, because the dose is small, so the harm to people is small. However, long-term exposure of pregnant women may affect the growth and development of the fetus, and may also jeopardize the health of the pregnant woman herself. Pregnant women should usually avoid contact with toxic and harmful substances, so as not to cause adverse effects on the fetus. Usually also pay attention to dietary intake, daily appropriate to eat more fish, shrimp, protein foods, but also can eat more fresh vegetables and fruits. It is recommended that pregnant women do regular pregnancy checkups, do not use tetrafluoroethrin, so as to avoid some adverse consequences, if there are abnormalities after inadvertent exposure, we must seek medical attention in time.