safe period

n.

（妇女避孕）安全期；

safe period
Safe periods both explain and need explaining.
The "safe period"as a birth control measure: A study and evaluation of available data.
Climatic Analysis on the Safe Period of Seed Production of the Two-line Hybrid Rice
Is early laparoscopic cholecystectomy safe after the "safe period"?
Hypothermia: halothane anesthesia and the safe period of total circulatory arrest
Human Reproduction. (Book Reviews: Science and the Safe Period. A compendium of human reproduction)
Intramyocardial carbon dioxide tension. A guide to the safe period of anoxic arrest of the heart.
Prolongation of safe period of venous inflow occlusion in hypothermic state by coronary and carotid artery perfusion with oxygenated...
Normothermic anoxic arrest of the heart. Is there a means of estimating the safe period?