Creighton Model Effectiveness, Intentions and Behaviors Assessment (CEIBA)

There are a variety of natural family planning (NFP) methods available today that differ in
algorithm and biomarkers used to identify women's fertile window. This study will directly
evaluate the NFP system known as the Creighton Model FertilityCare System (CrM). The
Creighton Model System is a well-established educational system about fertility which
involves no devices. The CrM teaches women a standardized way of observing and describing
their vaginal discharge each day during routine use of the bathroom, and interpreting the
changes in vaginal discharge to determine whether they are likely to be fertile that day or
not. Vaginal discharge changes as tracked by the CrM are an accurate indicator of the
changes in secretions from the uterine cervix that relate to the approach of ovulation.

This study will also examine the relationship between a couple's stated intentions to
achieve or avoid a pregnancy during each menstrual cycle with their sexual behavior during
the same cycle. There is growing consensus among researchers that current measures of
pregnancy intention are simplistic at best, and at worst can be very misleading. One of the
purposes of the study is to explore the multiple dimensions of pregnancy motivations,
intentions, and behaviors by newer detailed measures.

This study will enroll couples who are new or returning CrM users and who are trying to
avoid a pregnancy at the time they begin use of the CrM. The participants will be recruited
from CrM FertilityCare Centers. The design is a prospective cohort study, which is the
optimal study design to assess different measures of effectiveness and intendedness
simultaneously in a group of NFP users. Several of the key measures of intention and
behavior required for this study must be assessed prior to the outcome of actual use of CrM
over time and the outcome of pregnancy, to avoid recall bias. Outcomes for this study
require relatively precise assessment of the timing of both intentions and behaviors, which
is simply unavailable from recall. We plan to enroll at least 300 and up to 400 couples in
the study. This represents 60% (300/497) of the estimated available and eligible couples
learning the CrM for use to avoid pregnancy in one year at the participating FertilityCare
Centers.