Smith, K. R., Varner, M. W., & Stanford, J. B. (2014). Impact of instruction in the Creighton model fertilitycare system on time to pregnancy in couples of proven fecundity: results of a randomised trial. Paediatric and Perinatal Epidemiology, 28(5), 391-399. https://doi.org/10.1111/ppe.12141
Smith KR, Varner MW, Stanford JB. Impact of instruction in the Creighton model fertilitycare system on time to pregnancy in couples of proven fecundity: results of a randomised trial. Paediatr Perinat Epidemiol. 2014;28(5):391-399. doi:10.1111/ppe.12141
Smith, K. R., et al. "Impact of instruction in the Creighton model fertilitycare system on time to pregnancy in couples of proven fecundity: results of a randomised trial." Paediatric and Perinatal Epidemiology, vol. 28, no. 5, 2014, pp. 391-399.
Proven-fertile women taught Creighton conceived as often as controls
A randomized trial of 143 women of proven fertility found women taught the Creighton Model FertilityCare System conceived at rates similar to controls. Within seven cycles, 78 out of 100 taught women and 79 out of 100 controls conceived. In the first cycle, 4 out of 100 taught women and 17 out of 100 controls conceived.
Conceived within seven cycles: Creighton Model FertilityCare, 78 in 100; Controls, 79 in 100. Source: Smith KR et al., 2014, PMID 25225008.Study at a glance, randomized trial of 143 women of proven fertility: Proven-fertile women taught Creighton conceived as often as controls. Source: Smith KR et al., 2014, PMID 25225008.
Key Findings
The trial randomized 143 women: 72 to instruction in the Creighton Model FertilityCare System (CrMS, 69 analyzed) and 71 to controls advised to have intercourse 2–3 times per week.
Within seven cycles, 56 controls (79%) and 54 CrMS women (78%) conceived, and the adjusted hazard ratio for time to pregnancy was 0.86 (95% CI: 0.53, 1.38).
Among cycles with intent to conceive, fecundability (chance of pregnancy per cycle) was 36% with CrMS and 31% in controls (p=0.32).
Fecundability in the first cycle was 17% (12/71) in controls and 4% (3/69) with CrMS (p=0.02).
Over cycles 2–7 with intent to conceive, adjusted cumulative pregnancy probability by cycle 3 was 63% with CrMS (95% CI 51% to 74%) and 51% in controls (95% CI 40% to 63%).
Interpretation
The study was a parallel randomized trial of women ages 18–35 who had a prior pregnancy and no history of reduced fertility. All participants were asked to begin trying to conceive in the second cycle. The authors believe that the CrMS group had a more compelling reason to wait, learning mucus patterns before semen is present, so more CrMS women followed the instruction. The authors also note that models predict a smaller effect of timing intercourse in couples with more frequent intercourse or higher baseline fecundity.
RRM Context
Restorative reproductive medicine builds on cycle charting. The Creighton Model FertilityCare System teaches women to track and read vaginal secretions that mark the fertile window. The authors cite a randomized trial of 653 women who had tried to conceive for up to 2 years. Women using a monitor to identify the fertile window conceived at a significantly higher rate in the first two cycles. They also cite an observational study of 448 women ages 30–44 that linked consistent mucus checking to a fecundability ratio of 2.1 (95% confidence interval 1.16 to 3.81).
Our editorial summary of this paper, not the article's abstract.
Abstract
Background
The Creighton Model FertilityCare System (CrMS) teaches women to identify days when intercourse is likely to result in pregnancy. We sought to assess the impact of the CrMS on time to pregnancy (TTP), via per-cycle pregnancy rates (fecundability).
Methods
We conducted a parallel randomised trial at the University of Utah School of Medicine, 2003-06. Women ages 18-35 years, in a relationship of proven fertility, who desired to conceive, were block-randomised and stratified for age, with allocation concealment by opaque sequentially numbered sealed envelopes. The control group received the advice to have intercourse 2-3 times per week, and the intervention group received CrMS instruction. All women were asked to begin trying to conceive starting the second cycle in the study and were followed actively up to seven cycles, without blinding of research personnel. We calculated descriptive statistics and fecundability, and estimated Cox models for TTP. (Clinicaltrials.gov NCT00161395).
Results
There were 143 women randomised: 71 to the control group (all analysed) and 72 to the CrMS group (69 analysed). The adjusted hazard ratio for the influence of CrMS on TTP was 0.86 [95% confidence interval (CI): 0.53, 1.38]. Fecundability in cycles with intent to conceive was 31% in controls and 36% with CrMS (P = 0.32). By the first cycle, fecundability was 17% in controls, and 4% with CrMS (P = 0.02). No adverse events were reported.
Conclusions
We found no significant impact of CrMS on TTP or fecundability, but fewer of the women receiving CrMS conceived by the first cycle.
Clinician-reviewed comparison of fertility awareness-based methods (Billings, Creighton, Sensiplan, Marquette, Standard Days, apps). Every effectiveness figure cited and labeled by metric.
NaProTechnology diagnoses and treats the underlying conditions driving infertility, menstrual disorders, and early pregnancy loss. This guide covers how the method works, published outcomes data, how to find a qualified provider, and what to expect on cost and insurance.
Joe Stanford, Joey Stanford, J Stanford, Kenneth Smith, K Smith, Mike Varner, M Varner
PMID 25225008 25225008 DOI 10.1111/ppe.12141 10.1111/ppe.12141 Smith et al. 2014, Smith 2014
Keywords
Adolescent, Adult, Female, Humans, Sex Education/methods, Time-to-Pregnancy, Treatment Outcome, Young Adult, Time to Conception, Fecundity, Natural Family Planning, Preconception, Randomized Trial, Time to Pregnancy
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