This report discusses the effectiveness, acceptability and feasibility of periodic abstinence in family planning programs.  The concept of periodic abstinence had its beginnings during the 1930's when Drs.

 A report on the state of knowledge, current research, and potential effects of sex preselection in humans is presented.  The chromosomal mechanism by which the male gamete determines the sex of the offspring is reviewed.  Theoretically, the sex ratio should be 1:1, though there is a slight preponderance of males to females in the world birthrate.  More than 30 variables have been associated with the variations in the sex ratio.

 Despite the advances of modern medicine, the only method of birth control which is completely safe and completely effective is complete sexual abstinence. For millenia individuals trying to control their own fertility as well as institutions trying to control social mores have experimented with various forms of culturally enforced sexual abstinence such as late marriage, long lactation without intercourse, celibacy for the clergy, isotation of women, and strong taboos associated with menstruation, childbirth, and close blood ties.