In recent years increasing interest has focused on the symptoms that accompany normal ovulation. 'Identifying the accuracy ofthese symptoms as indicators of ovulation is of practical importance both to the subfertile couple trying to maximise the chance of conception and to the couple using" natural fiaily planiing" to prevent conception. Until recently it has not been possible to assess the accuracy of the symptoms because of difficulties in assessing the exact time of ovulation. Ovarian ultrasonography has now been shown to allow accurate …