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).
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
Postpartum / Breastfeeding Protocol
198 postpartum women ages 20-45 using 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
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