The purpose of this research study is to compare the effectiveness of two natural family planning (NFP) methods that are provided over the internet by the Marquette University Institute for Natural Family Planning. One of the NFP methods is the use of a hand held electronic hormonal fertility monitor. The other method involves the self-observation of cervical mucus to track fertility. Both of the methods will involve placing information about fertility into an online charting system that automatically displays the days of fertility and infertility. The investigators are also interested in the influence of mutual motivation by the woman and her partner in using these methods to avoid pregnancy. The investigators hypothesize that there will be lower unintended pregnancy rates among those couples who use the electronic hormonal fertility monitor and among those couples who have a strong motivation to avoid pregnancy.

The Office of Population Affairs (OPA) of the Department of Human Development recently submitted a call for proposals for research on methods of natural family planning (NFP). The department chairs of OPA have recognized that relatively few women in the United States use natural methods of family planning, especially in the Title X Family Planning programs and clinics. They wanted researchers to develop studies to help increase the use and the efficacy of these methods, and, furthermore, wanted to understand why the methods are not used more. Reasons why only about 0.2% of US women use natural methods of birth control are they are often difficult to use, they are relatively ineffective, and there is a lack of access to properly trained NFP teachers. At Marquette University we have developed simple methods of NFP that utilize an electronic fertility monitor that measures female reproductive hormones, self cervical mucus monitoring that estimates the fertile window, and a simple fertility formula to help estimate the beginning and end of the fertile window. We also have developed a Web site that offers easy access to information on NFP, electronic charting, and professional nurses with specialization in teaching NFP.

The specific purpose of our study is to determine the efficacy, satisfaction, ease of use, and motivation in using an internet based NFP method that utilizes an electronic hormonal fertility monitor plus a simple fertility formula (i.e., EHFM-NFP) within an online professional-nurse supported system. Since there are few studies that compare methods of NFP, another aim of this study is to compare an internet based EFHM-NFP method with an internet based traditional cervical mucus monitoring (CMM) NFP method - both methods were developed at Marquette University. Please note that we have 3 published efficacy studies of the Marquette Method.

The specific research questions that will be asked are:

1. What are the 3, 6, and 12-month unintended pregnancy rates of an internet-provided EHFM-aided NFP method?
2. What are the 3, 6, and 12-month unintended pregnancy rates of an internet-provided CMM-only NFP method?
3. What is the satisfaction, ease of use, and mutual motivation of an internet-based NFP method (either EFHM or CMM) over a 12-month time period, i.e., after 1, 3, 6, and 12 months of use?

For Female participants

Inclusion Criteria:

• be between the age of 18 and 42
• be in a sexually active committed relationship with a man
• have a menstrual cycle range of 21-42 days

Exclusion Criteria:

• have not used Depo (injectable) contraception for the past 6 months
• have not used oral or patch hormonal contraception for the past 3 months
• have not breast-fed baby for at least three months
• have no known fertility problems
• not be using medications that interfere with fertility
• not smoke cigarettes; and
• not be pregnant.

For Male Participants

Inclusion criteria:

• be between the ages of 18 and 50
• be in a sexually active committed relationship with his lone woman partner.

Exclusion criteria:

• have no known fertility problems