There is no clinical magnesium sulfate medication four indications, clinical indications are generally hypertension in pregnancy, pre-eclampsia, eclampsia. Liver, kidney insufficiency should be strictly prohibited to use this drug, so as not to cause magnesium sulfate accumulation in the blood, inhibit the body excitability, so that the body response is slow, in serious cases may also cause cardiac arrest, life-threatening, it is recommended to use the drug strictly under the guidance of a doctor. 1, gestational hypertension: magnesium sulfate can play an antispasmodic effect, help to relax the smooth muscle of the blood vessels around the uterine cavity, so that the gestational blood pressure drop, promote the placental vascular increased blood flow, which is conducive to normal fetal development; 2, pre-eclampsia: impaired ability to infiltrate trophoblast cells outside the uterine villi can lead to increased vascular resistance around the uterus, the amount of blood flowing into the placenta is reduced, and magnesium sulfate can dilate the blood vessels, prompting an increase in the amount of blood flowing into the placenta, thus helping to alleviate the symptoms of pre-eclampsia; 3, eclampsia: usually refers to the placental factor into the maternal blood circulation, promoting inflammatory response activation and damage to the vascular endothelium, which can lead to headache, nausea, vomiting and other symptoms in pregnant women. Injecting magnesium sulfate under the guidance of a doctor can help improve such symptoms.