Grant Title

Randomized Comparison of Two Internet-Supported Methods of Natural Family Planning

Document Type

Contribution to Book

Publication Date


Source Publication

Science, Faith, and Human fertility: The Third Conference on Ethical Fertility Health Management

Source ISSN

9780874620931, 0874620937


The aims of this study were to determine and compare efficacy, satisfaction, ease of use, and motivation in using an internet-based method of Natural Family Planning (NFP) that utilizes either electronic hormonal fertility monitoring (EHFM) or cervical-mucus monitoring (CMM). Four hundred fifty women (mean age 30.1) and their male partners (mean age 31.9) who sought to avoid pregnancy were randomized into either an EHFM (N=228) or CMM NFP group (N=222). Both groups utilized a Web site that provided NFP instructions, an electronic charting system, and support from professional nurses. Participants were assessed for satisfaction, ease of use, and motivation in use of their respective NFP method at 1, 3, and 6 months. Unintended pregnancies were validated by pregnancy evaluations and urine tests. Correct and total pregnancy rates were determined by survival analysis. Correct and total 12 month unintended pregnancy rates for the combined participants (N=450) were 1 and 9 per 100 couple users (Std. Error = .01 and .02) respectively. The EHFM participants (N=228), however, had a typical unintended pregnancy rate of 6 (Std. Error = .03) compared to the CMM group (N=222) pregnancy rate of 13 (Std. Error = .04) per 100 users over 12 months of use. The mean satisfaction/ease of use score for the EHFM group at 6 months of use was 46.1 compared to 42.9 for the CMM group (p < .07). Motivation to avoid pregnancy was stronger for the CMM group compared to the EHFM group at 3 and 6 months of use (37.9 and 38.8 versus 33.7 and 33.4, p < .01). Although both NFP methods were highly effective methods of family planning delivered through a nurse supported Web site, at this time, the unintended pregnancy rate was lower for the EHFM group and compared well with hormonal contraception. Although acceptability of the EHFM NFP was high, motivation to avoid pregnancy with that group decreased over time.

Document Rights and Citation of Original

Published version. "Randomized Comparison of Two Internet-Supported Natural Family Planning Methods (Preliminary Findings)," in Science, Faith, and Human fertility: The Third Conference on Ethical Fertility Health Management. Eds. Richard J. Fehring and Theresa Notare. Milwaukee, WI: Marquette University Press, 2012: 131-147. Publisher link. © 2012 Marquette University Press. Used with permission.