Amenorrhea following oral contraception.

A prospective study was done on 326 nulliparous women who ceased oral contraception. Follow-up was obtained on 311. The mean age was 20.3 years (S.D. 2.5). Eighty-nine per cent began menstruating within 60 days after stopping therapy, and only 7 took 180 days or longer to menstruate. Late menarche strongly correlated with post-pill amenorrhea (PPA), but continous length of time on oral contraceptives and type of oral contraceptive showed no significant relationship. The incidence of PPA was 2.2 per cent. All women did eventually menstruate spontaneously, the longest period of amenorrhea being 540 days.