Periodic abstinence or 'the rhythm method' is a form of birth control based on a couple having intercourse only during the infertile or 'safe' period of the woman's monthly cycle. Calculations of the phases of the woman's cycle are also used by couples who wish to maximise their chances of conceiving, but in this case they try to have intercourse during the woman's fertile period. Periodic abstinence has been used throughout history by various racial groups, but it was not until the first half of the 20th century that the scientific basis of the menstrual cycle was understood and the 'safe' period could be calculated with some accuracy.
In 1932 Dr Leo J. Latz published 'The rhythm of sterility and fertility in women', using for the first time the term 'rhythm'. He described the recent work of scientists Ogino in Japan and Knaus in Austria, who separately confirmed that ovulation preceded menstruation by a fairly constant period of twelve to sixteen days.
Birth control had been a contentious issue within the Roman Catholic Church for decades. By 1930 Pope Pius XI was continuing to proclaim that any use of matrimony which deliberately frustrated the 'natural power to generate life' was 'an offence against the Law of God and of nature'. It was only after official approval by Pope Pius XII in 1951 that the Catholic Church accepted the rhythm method and it became widely promoted as a means of birth control. Because it has been the only method to receive official approval of the Catholic Church and the main protagonists have been Catholic, the 'rhythm method' has come to be closely identified with that church and its teachings, to the point where it has sometimes been called 'Vatican roulette'.
Since the 1930s there has been increased understanding of the naturally occurring signs and symptoms of the fertile and infertile phases of the menstrual cycle, and technologies have been developed to help women recognise and chart changes in, for example, their body temperature and cervical mucus. The 'rhythm method' is now usually referred to as 'natural family planning'.
Dr Latz's little 'Rhythm' book was reprinted many times. The copy in the Powerhouse Museum collection is from the personal belongings of Sydney woman Mrs Ellen Stephenson who was born in 1911. It was published 'with ecclesiastical approbation' in 1950 and was the sixth revised edition and the 22nd printing.
Siedlecky, Stefania, and Wyndham, Diana, Populate and perish: Australian women's fight for birth control, Sydney: Allen & Unwin, 1990.
Smith, Anne, conversations with Powerhouse curator, Megan Hicks, 1994-2005.