However, FDA does not accept fast-acting nifedipine as a treatment for emergency hypertension as well as the sub-lingual treatment as some evidences have demonstrated that the treatment may cause excessive reduction in blood pressure. It can be concluded from studies on treatment of hypertension in pregnancy that the selection of antihypertensive treatment should depend on experiences and knowledge of doctor who is treating the patient, particularly in terms of the maternal and fetal effect of the drug. Although there is no clinical study that provides any evidence of how much reduction in blood pressure is considered to be optimal, many have suggested a target systolic blood pressure of 140-150 mmHg and diastolic blood pressure of 90-100 mmHg. In pregnant women who have experienced target organ damage, it is suggested to reduce the blood pressure to less than 140/90 mmHg until it reaches 120 and 80 mmHg.