Hormonal control of conception.

Prior to 1938 no form of oral hormonal contraception was possible as none of the then availablehormones were active when given orally. The era of oral contraception commenced withthe reports of Pincus et al (3). The contraceptive pills used today contain a synthetic oestrogenand a synthetic progestational agent. Oestrone and oestradiol were available prior to 1938as esters but these were active only when injected. Impure injectables indicated then that they could prevent pregnancy.