Methods of family planning based upon identifying the days of potential fertility in women, known as natural family planning (NFP) or fertility awareness-based methods (FABMs), are an important option for family planning (1–4). These methods use various biomarkers to identify days in the menstrual cycle when intercourse is likely to result in pregnancy. Among their advantages are low cost, lack of side effects, and the education they can provide users about their own reproductive physiology and health (5–7). By definition, NFP refers to avoiding pregnancy through abstinence from genital contact (8, 9), while FABM allows for the use of barriers or withdrawal on fertile days—as well as abstinence—when pregnancy avoidance is intended (10, 11).

In addition to their use in avoiding pregnancy, FABM or NFP methods are unique among family planning methods in their additional ability to help couples try to time pregnancy (12–14). Indeed, in population-based studies, potential interest in these methods has been greater for the purpose of conceiving than of avoiding conception (15, 16). Many, perhaps most, long-term users of FABM or NFP methods will at different times use the method both to avoid pregnancy and to conceive, transitioning between these intentions (17–19).

The Creighton Model FertilityCare^TM System (CrM), a NFP method based on initial research at St. Louis University, was further developed and implemented by Dr. Hilgers and colleagues at the Creighton University Medical Center and the Pope Paul VI Institute for the Study of Human Reproduction, Omaha, Nebraska (20, 21). It is based on standardized observation and recording of vaginal discharge (especially from cervical mucus) and vaginal bleeding, interpretation of these biomarkers for fertility and health status, and teaching using a case management approach (22). The CrM instructors are called Creighton Model FertilityCare^TM Practitioners (CrM FCPs). CrM instruction is provided through Creighton FertilityCare^TM Centers; in the United States and Canada, these are registered through FertilityCare^TM Centers of America, while in other parts of the world they are registered through FertilityCare^TM Centers International (www.fertilitycare.org). Additionally, a system of medical protocols called natural procreative technology (NaProTechnology) has been developed for supporting women with gynecologic problems and couples with infertility and integrated with the CrM (23). Integral to the teaching of the CrM is emphasizing to the couples that they have radical autonomy to choose to have intercourse or not on any given day with full knowledge of the possibility of pregnancy on that day (“selective intercourse”) and that there is no requirement for what they “should” do with regard to possible pregnancy outcomes (22).

Several previous studies have been published regarding the CrM’s effectiveness in both promoting or preventing pregnancy (24–30). These studies were based on assessments of the couples’ behavior and knowledge; they made very limited assessment of the relationships between intentions, behaviors, and pregnancy rates. The study of Creighton Model Effectiveness, Intentions, and Behaviors Assessment (CEIBA) was conducted to assess the spectrum of fertility motivations, intentions, and fertility-related sexual behaviors and quantify their impact on effectiveness in avoiding or achieving pregnancy among new users of the CrM with initial pregnancy avoidance intentions. In this paper, we report on the recruitment for CEIBA, baseline demographic characteristics, and the childbearing motivations and intentions of women and men (heterosexual couples) who started use of the CrM with the initial intention of avoiding pregnancy. We also describe the protocol for assessing follow-up intentions, behaviors, and pregnancy.

A total of 1,132 new or returning couples were seen across all centers: 1,090 (96%) were screened, and of those screened, 429 (39%) were eligible couples of which 305 women (71%) consented to the study, along with 290 of their male partners (95%). The number of couples enrolled per month ranged from 0 to 30, with a median of 10 enrollments per month. The 305 women were enrolled across all 17 sites. The minimum number enrolled per sites was 2, the maximum was 60, and the median enrollment per site was 16. Table 1 lists reasons for the 704 women excluded from the study (43 who did not complete screening and 661 who were not eligible), including the reasons for not completing screening or for ineligibility.

Most participants were engaged (39%) or married (51%), college graduates (77% of women), Caucasian non-Hispanic (80% of women), and Catholic (80% of women). There were demographic differences between couples who enrolled in the CEIBA study, and couples seen during the same time who were not enrolled. Women who enrolled were more likely to be of age 20–29 years, to be engaged (versus married or single), to have a college-level education, to have lower household income, to be Catholic, and to have no prior pregnancy or live birth (Table 2). Similar patterns were found for men’s age, marital status, education, and religion. There was a high level of religious involvement: 79% of women and 67% of men reported attending religious or worship service at least once per week. The mean age of women enrolled was 27.8 years.

The most common previously used family planning methods were the oral contraceptive pill (60%) and the male condom (57%) (Table 3). Twenty-two women had previously used the CrM to avoid pregnancy, and 11 women had previously used the CrM to conceive. Overall, there were 27 of all consented women who had previously used the CrM in either way, representing 8.9% of all women enrolled. These women were eligible and enrolled under the expanded criteria (described above) because they were returning to use of the CrM after a pregnancy or other time period of not using the CrM.

Reasons reported for starting (or resuming) the use of the CrM are indicated in Table 4. For women, the most common reasons were to use a natural method (91%), for moral/ethical/religious reasons (70%), the lack of side effects (71%), or insight into the menstrual cycle and fertility (62%). For men, the most common reasons were to use a natural method (76%), moral/ethical/religious reasons (70%), for wife/partner’s choice (62%), and lack of side effects (61%).

Desires, intentions, and motivations for future childbearing are presented in Table 5. At the median, women intended to have three additional children (range 0–11); while men intended to have two additional children (range −2 to 10). About one in five women (21%) intended to have a child within a year, and 60% between 1 and 3 years. The majority of women reported that their closest family members (55%) and closest friends (57%) would be in favor of them having a child at the present time. The mean positive childbearing motivation score for both women and men was 3.3 (range 1–4, with 4 being most positive).

We examined factors related to desire for children, with results presented in Table 6. In the each of the models for Tables 6 and 7, we included all variables that were significant in any one of the models. For both women and men, the number of future children desired was positively correlated with positive childbearing motivation scores and perception of spouse or partner’s desired number of future children. Number of future children desired was negatively correlated with age, negative childbearing motivations, number of prior live births, and past use of any hormonal contraception, IUD, or emergency contraception. Marital status was not correlated. Altogether, these variables accounted for over half of the variance (adjusted R²) for number of future children wanted for both women and men.

We also examined factors related to intention for children, with results presented in Table 7. As expected, the number of future children intended was most strongly correlated with number of future children wanted. Positive correlations were also present with perception of number of future children wanted by the spouse or partner, especially for men. There was a negative association for being married (in comparison with mostly engaged couples), and number of prior live births (for men only). For men, there was a positive association with positive childbearing motivations, but no other association with childbearing motivations score for women and men. Altogether, these variables accounted for about 75% of the variance (adjusted R²) for number of future children intended for both women and men.

We recruited 305 couples to a prospective study of the CrM for family planning. The majority was engaged or married, college graduates, and Catholic. All CrM centers serve women and couples of any faith (or no faith), but the association with Catholic institutions means that the exposure and accessibility to the CrM is greater for Catholic couples. In addition, the majority of women (70%) and men (61%) cited moral/ethical/religious reasons as a motivator for learning the CrM, and many women (40%) and men (42%) indicated that they were motivated by the method being suggested by a religious leader. This is consistent with a study in Germany and Poland which found that, while interest in NFP was not associated with religious motivation, the actual use of NFP was associated with Catholic affiliation (17).

Consistent with eligibility criteria for the study, all couples were originally planning to avoid (or space) pregnancy, but the vast majority had high levels of childbearing motivation, desire, and childbearing intention for the near future. Among women, 69% wanted a child within 3 years, while 71% of men wanted a child within 3 years. It is instructive to compare the positive and negative childbearing motivation scores of the CEIBA couples with those of 401 couples in California in a 1995 study (33). In the California study, all the couples were married: half had no children and had been married for a mean of 3.1 years, and half had one child and had been married for a mean of 4.7 years; also they were somewhat older and wealthier than the couples in the CEIBA study. The mean positive childbearing motivation score in the California study was 2.9 and 2.8 for women and men, respectively. The mean negative childbearing motivation score was 2.2 and 2.4, respectively. The mean total number of children desired was 2.5 for both women and men. In comparison, our sample had higher positive childbearing motivation scores (mean 3.3 for both women and men), lower negative childbearing motivation scores (mean 2.1 and 2.4 for women and men, respectively), and a much higher total number of children wanted (median of 4 for women and 3 for men). This high level of childbearing motivations, desires, and intentions may represent a strong proceptive influence from high levels of involvement in Catholicism and perhaps other religions (36, 37). In addition, CEIBA participants reported that friends and family members were highly supportive of childbearing.

A minority (39%) of screened new users at the participating centers was eligible for the study. Among those who were ineligible, 59% were learning the CrM to try to conceive and 48% had a medical history of infertility. This represents a significant shift from a study conducted more than 10 years ago across eight CrM centers in the United States, which enrolled new CrM users from 1996 to 2000 (38). In that study, only 19% of new users were trying to conceive at study entry. This shift may also be consistent with current trends for the use of fertility apps for smart phones and other personal mobile computing devices, most of which seem to emphasize seeking pregnancy rather than avoiding pregnancy (1).

Because NFP methods can be used either to avoid pregnancy or to conceive, assessing users’ intentions is essential to assessing any NFP method’s effectiveness (12, 13, 18, 39). The CrM educational materials and interactions emphasize radical autonomy for the couple, who decides whether to use it to avoid pregnancy or to conceive (28, 40). Consistent with this philosophy, past evaluations of pregnancy rates with the CrM have been based on behavioral evaluation, rather than stated intentions (25, 28, 29). This contrasts with contraceptive methods that have only the purpose of avoiding pregnancy, and in which prospectively stated intentions have been standard for assessing pregnancy rates (41). One of the purposes of the CEIBA study is to compare intention-based measures of pregnancy rates with behaviorally based measures.

According to the well-established Theory of Reasoned Action and similar theories, intentions are largely driven by desires, and are also influenced by social norms. In turn, desires are largely formed by motivations, as well as other factors (42, 43). Our findings for number of pregnancies wanted and intended by women and men are consistent with this framework. In future analyses, we will assess quantitatively the relationships between desires, intentions, behaviors, and fertility outcomes (i.e., pregnancy) in this study population.

Women/couples beginning use of the CrM to avoid pregnancy within the United States and Toronto, Canada are mostly young, religious, engaged or newly married, Roman Catholic, and have high levels of motivation, desire, and intention for future childbearing, with the large majority of both women and men wanting a child within 3 years. The CEIBA study assessed these factors at baseline and implemented prospective measures of each of desires, intentions, and sexual/fertility behaviors for up to 1 year after beginning sexual activity. These data will allow us to assess the impact of desires, intentions, and behaviors on the incidence of pregnancy among these couples.

The study was reviewed and approved by the University of Utah Institutional Review Board, IRB number 00034487. All local participating sites either had local IRB approval or an authorization agreement relying upon the University of Utah IRB.

JS was the principal investigator for designing and implementing the CEIBA study, directed the data analysis, and wrote the manuscript. CP served as coinvestigator to conduct the study, provided guidance for the analysis, and helped revise the manuscript.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.