Effectiveness of the CREIGHTON MODEL System to Avoid and to Achieve Pregnancy Joseph B. Stanford, MD, MSPH, CNFPMC Associate Professor Family and Preventive Medicine University of Utah School of Medicine

Why study use to avoid and achieve? Couples who use CrM throughout their life will use it both ways. In any CrM program, users will come for both reasons. Interest in NFP to achieve is higher than interest to avoid (in USA). –About 33% interested to avoid; 25% to achieve –Missouri and Utah

What is the effectiveness of CrM to avoid pregnancy? What is the effectiveness of CrM to achieve pregnancy? How do you distinguish between use to avoid and use to achieve? What are the needs for future research?

What is the effectiveness of CrM to avoid pregnancy? What is the effectiveness of CrM to achieve pregnancy? How do you distinguish between use to avoid and use to achieve? What are the needs for future research?

Distinguishing between use to avoid and use to conceive Unplanned and planned pregnancy Achieving-related pregnancy

Pregnancy from genital contact during known fertile time (Un)planned pregnancy Fertility control Responsibility for pregnancy belongs to the method. Subjective, superficially measured. Achieving-related pregnancy Fertility cooperation Responsibility for pregnancy belongs to the couple. Objective, based on knowledge and behavior.

Pregnancy from genital contact during known fertile time (Un)planned pregnancy Sex and fertility are fantasized to be completely separate phenomena. “Unplanned” is usually considered to be a negative outcome. Achieving-related pregnancy Sex and fertility are naturally and inseparably related. Achieving-related pregnancy is almost always considered to be a positive outcome.

Consider 2 family planning methods Inserted by doctor. Suppresses fertility. Has to be removed by doctor. Encourages couple to forget about their fertility. Low method pregnancy rate. Low total pregnancy rate. “Planned” Parenthood Used by couple. Cooperates with fertility. Couple is continually encouraged to consider the gift and possibility of fertility. Low method pregnancy rate. Higher total pregnancy rate. Responsible Parenthood

Distinguishing between use to avoid and use to achieve (CrM) Use to avoid is avoidance of genital contact during known times of fertility. –Avoiding-related pregnancy Use to achieve is any genital contact during known times of fertility. –Achieving-related pregnancy Couples rarely have any difficulty grasping and accepting this approach.

What is the effectiveness of CrM to avoid pregnancy? What is the effectiveness of CrM to achieve pregnancy? How do you distinguish between use to avoid and use to achieve? What are the needs for future research?

Avoiding-related pregnancy rates During use to avoid, method-consistent –method-related pregnancy rate –if method always used perfectly to avoid pregnancy During use to avoid, method-inconsistent –use-related pregnancy rate –as method is used in “real life” includes errors by user and/or teacher Either of these can be calculated with full- denominator or specific denominator. –Illustrate with method-consistent use

Method (perfect use) pregnancy rates during use to avoid a b Perfect use = a / [1+2] {full denominator; traditional measure} Perfect use = a / [1] {specific denominator; new measure} 2= cycles of “real life” use with errors; b= pregnancy due to error 1= cycles of method-consistent use; a= perfect use pregnancy

Statistical approaches Pearl rates –Influenced by length of follow-up (more=lower) Net life table (multiple decrement) –Influenced by rate of discontinuation Gross life table (single decrement) –Independent of rate of discontinuation –Higher rates than net life table Kaplan-Meier (similar to life table) Cox Proportional Hazards Regression –Multivariate modeling

Method (perfect) use pregnancy rates during use to avoid Selected CrM studies, full denominator, 12-month LocationYearCouple- months NET Pregnancy Rate per 100 GROSS Pregnancy Rate per 100 Wichita Houston USA, 5 sites199814,

Avoiding use pregnancy rates Selected CrM studies, full denominator, 12-month LocationYearCouple- months NET Pregnancy Rate per 100 GROSS Pregnancy Rate per 100 Wichita Houston1989, USA, 5 sites199814,

CrM Effectiveness Important Factors Standardized method Personalized instruction Competent, trained teachers Motivation Couple communication Not Important Regular cycles Educational status Socioeconomic status Religious denomination

What is the effectiveness of CrM to avoid pregnancy? What is the effectiveness of CrM to achieve pregnancy? How do you distinguish between use to avoid and use to achieve? What are the needs for future research?

1.The achieving related pregnancy rate is a demographic measure of consciously chosen fertility in the population over all cycles of use (full denominator) May include many cycles used to avoid 2.Normal fertility, pregnancy rate in cycles used to achieve (specific denominator) Includes only cycles used to achieve 3.Infertility, pregnancy rate (specific denominator) Essentially includes only cycles used to achieve With or without Natural Procreative Technology Effectiveness to achieve pregnancy

Selected studies of CrM to achieve CrM StudyDenominatorCouplesPregnancy Rate per 100 Comments Meta- analysis, 1998 Full- all study cycles/months net 28.2 gross Normal fertility Many couples in study never tried to achieve pregnancy Fertility- focused intercourse study Specific- only cycles to achieve 5076 in first cycle; 100% at 7 cycles Normal fertility Excluded couples not conceiving (retrospective) Irish Medical NPT Study Specific- only cycles to achieve up to 24 months Infertility Mean age 36 years 29% previously failed IVF

Effectiveness in infertility, method issues Per cycle success rates are not appropriate for CrM (or any infertility treatment). –Biased measures used extensively for IVF and related techniques. Cohort-based measures are appropriate for CrM, and to compare CrM to other infertility treatments. Crude rates will underestimate effectiveness. Traditional life tables will overestimate effectiveness (but probably less for CrM than for IVF).

CrM: effectiveness summary With exact use to avoid pregnancy, yearly pregnancy rates are less than 1 per 100. Accounting for user or teacher error, the yearly avoiding pregnancy rates are 2 to 5 per 100. –Effective teaching required. –CrM can be used in all reproductive situations to avoid. Irregular cycles, discontinuing oral contraceptives, breastfeeding (Most clearly shown in Creighton Model Texas study, 1999)

CrM: effectiveness summary Nearly all pregnancies among CrM users result from intercourse during known fertile days. –The total pregnancy rate in CrM studies ranges from 17 to 33 at one year (per 100, Net). –The achieving-related pregnancy rate ranges from 14 to 30 at one year (per 100, Net). –Achieving-related pregnancy varies by external circumstances (ie, unemployment rates)

CrM: effectiveness summary CrM is the method of choice for seeking pregnancy in infertility. –Depending on underlying age and diagnoseis, pregnancy rates without NPT may be around 33% –With Natural Procreative Technology, pregnancy rates will be 40-80% or even higher, depending on underlying age and diagnosis.

What is the effectiveness of CrM to avoid pregnancy? What is the effectiveness of CrM to achieve pregnancy? How do you distinguish between use to avoid and use to achieve? What are the needs for future research?

Evaluating CrM Effectiveness We need new CrM studies with the “specific denominator” approach for both avoiding and achieving pregnancy. We especially need studies in –Breastfeeding women (avoiding) –Premenopause (avoiding) –Normal fertility (prospective, achieving) –Women using yellow stamps (postpeak and prepeak) –Different subtypes of infertility with medical or medical+surgical NPT We need thorough, sound studies of the dynamics of achieving-related use.