The Journal of Reproductive Medicine, 37(10), 864-866, 1992
Fifty consecutive clients achieved pregnancy using a standardization modification of the Billings ovulation method (the Creighton Model Natural Family Planning System). Of 50 clients followed, 38 (76%) achieved pregnancy in the first cycle of fertility-focused intercourse, 45 of 50 (90%) achieved pregnancy by the third cycle and 49 of 50 achieved pregnancy by the sixth cycle (98%).
Hilgers, T. W., Daly, K. D., Prebil, A. M., & Hilgers, S. K. (1992). Cumulative pregnancy rates in patients with apparently normal fertility and fertility-focused intercourse. *The Journal of reproductive medicine*, *37*(10), 864-866.
Hilgers TW, Daly KD, Prebil AM, Hilgers SK. Cumulative pregnancy rates in patients with apparently normal fertility and fertility-focused intercourse. J Reprod Med. 1992;37(10):864-866.
Hilgers, T. W., et al. "Cumulative pregnancy rates in patients with apparently normal fertility and fertility-focused intercourse." *The Journal of reproductive medicine*, vol. 37, no. 10, 1992, pp. 864-866.
Adult, Cervix Mucus, Female, Follow-Up Studies, Humans, Natural Family Planning Methods, Pregnancy, Prospective Studies, Cervical Mucus Method, Coitus, Data Aggregation, Demographic Factors, Family Planning, Family Planning, Behavioral Methods, Fertility, Fertility Measurements, Menstrual Cycle, Menstruation, Natural Family Planning, Parity, Population, Population Dynamics, Pregnancy Rate, Reproduction, Research Methodology