Research articles

  • A key concept in understanding the effectiveness of a contraceptive method or natural family planning method is typical and perfect use rates.

  • Typical use indicates how effective a method is under "“real life” conditions (i.e. when users do not always use the method correctly 100% of the time).

  • Perfect use indicates how effective a method is under ideal conditions (i.e. when users use the method correctly 100% of the time).

  • Secondly, studies quote the Pearl rate/index, which is an approximate measure of the number of unintended pregnancies per 100 users over 12 months (i.e. if 100 women used the method over 1 year, how many of them would get pregnant?).

  • Below are brief summaries of a few studies that demonstrate the effectiveness of the Marquette Method. This section will be updated periodically with more recent articles.

Effectiveness of Marquette for avoiding pregnancy

  • Randomized comparison of Marquette monitor vs mucus methods (note: Marquette has a separate protocol, which uses changes in cervical mucus to identify the fertile window) for women with regular cycles (range 21-42 days)

  • Randomized to monitor group (N = 197) or mucus group (N = 160)

  • Monitor group: unintended pregnancy rate 7 per 100 users over 12 months; with perfect use, 0 per 100 users

  • Mucus group: unintended pregnancy rate 18.5 per 100 users over 12 months; with perfect use, 2.7 per 100 users

  • Conclusion: with perfect use, efficacy of Marquette monitor and mucus methods are very good (98-100%) and comparable to the pill

Fehring, R. J., Schneider, M., Raviele, K., Rodriguez, D., & Pruszynski, J. (2013). Randomized comparison of two Internet-supported fertility-awareness-based methods of family planning. Contraception, 88(1), 24-30.

Original Postpartum / Breastfeeding Protocol

  • 198 postpartum women ages 20-45 using original postpartum protocol

  • Result – 8 unintended pregnancies per 100 women at 12 months; 2 pregnancies with perfect use

  • Conclusion: Marquette postpartum/breastfeeding protocol is effective for avoiding pregnancy

Bouchard, T., Fehring, R. J., & Schneider, M. (2013). Efficacy of a new postpartum transition protocol for avoiding pregnancy. The Journal of the American Board of Family Medicine, 26(1), 35-44.

Updated Postpartum / Breastfeeding Protocol

  • 207 postpartum women ages 18-45 using updated postpartum protocol

  • Result – 4 unintended pregnancies per 100 women over 12 cycles; 2 pregnancies with perfect use

  • Conclusion: Updated Marquette postpartum/breastfeeding protocol remains effective for avoiding pregnancy

Schneider, Mary M., Richard J. Fehring, and Thomas Paul Bouchard. "Effectiveness of a Postpartum Breastfeeding Protocol for Avoiding Pregnancy." The Linacre Quarterly 90.2 (2023): 182-193.

Multisite effectiveness study

  • Retrospective longitudinal (12 month) cohort study including over 1000 women from multiple teaching sites in North America

  • Included women in regular cycles, postpartum/breastfeeding, and irregular cycles

  • Result – total unintended pregnancy rate over 12 months (typical use):

    • 2.8 per 100 women (regular cycles), 8 per 100 women (postpartum/breastfeeding), 4.3 per 100 women (irregular cycles)

  • Conclusion: High level of effectiveness in using Marquette for women from various regions across North America with diverse reproductive backgrounds

Mu, Qiyan, Richard J. Fehring, and Thomas Bouchard. "Multisite effectiveness study of the Marquette method of natural family planning program." The Linacre Quarterly 89.1 (2022): 64-72.

Evidence for achieving pregnancy

  • Followed 124 women using Marquette mucus or monitor methods (or both) to try to achieve pregnancy

  • Pregnancy rates 81 per 100 women at 12 months of trying when intercourse happened on high/peak days of fertile window

  • Pregnancy rate 6 per 100 women when intercourse happened only on low days of fertile window

  • Conclusion: focusing intercourse on high or peak fertile days using the Marquette method increases probability of achieving pregnancy

Mu, Q., & Fehring, R. J. (2014). Efficacy of achieving pregnancy with fertility-focused intercourse. MCN: The American Journal of Maternal/Child Nursing, 39(1), 35-40.