A prospective multicenter trial of the ovulation method of natural family planning. V. Psychosexual aspects. World Health Organization.

During the 13-cycle effectiveness phase of a five-center study of the ovulation method of natural family planning, there were substantial differences, particularly between the two developed and the three developing countries, in the stated degree of satisfaction with the frequency of intercourse (most couples were satisfied in Bangalore, Manila, and San Miguel, whereas one-third of the subjects and half of their partners would have preferred more frequent intercourse in Auckland and Dublin) and in expressed difficulties associated with abstinence (e.g., 62% had occasional difficulty in Auckland, 14% in Bangalore, 55% in Dublin, 28% in Manila, and 5% in San Miguel). Cumulative net probabilities of discontinuation due to pregnancy were 1.8%, 18.6%, and 54.7% for couples in whom the male partner's degree of satisfaction was described as "no difficulty," "occasional difficulty," and "always some difficulty," respectively.