Achieving-Related Pregnancy Rate (ARPR)

By RRM Academy Reviewed by Dr. Naomi Whittaker, MD, Board-Certified OBGYN, MIGS, NFPMC, FCI Updated May 14, 2026

The Achieving-Related Pregnancy Rate (ARPR) is a use-effectiveness statistic developed within the Creighton Model FertilityCare System to measure pregnancy outcomes specifically among couples who have transitioned from avoiding conception to actively attempting it.¹ Unlike generic cumulative pregnancy rates, the ARPR isolates cycles in which fertility-focused intercourse was timed to the fertile window identified by Creighton Model charting. The denominator is controlled for intent and method use, which makes the resulting rate a more meaningful measure of fertility potential than unselected exposure statistics.

The methodological distinction matters. Most fertility effectiveness figures in reproductive medicine, including per-cycle clinical pregnancy rates used in ART, count all exposure cycles regardless of whether intercourse was timed to the fertile phase. The ARPR accounts for intent and method adherence. A couple timing intercourse to peak fertility using cycle data is not statistically comparable to a couple having intercourse without cycle awareness, and the ARPR reflects that difference.²

The ARPR is the foundational effectiveness measure underlying NaProTechnology achieving outcomes data and is referenced in treatment outcome analyses for conditions including luteal phase deficiency and endometriosis-related subfertility.³ It is also used to contextualize outcomes in the Fertilitas Study, the largest published NaProTechnology infertility cohort to date.⁴ For NaPro Medical clinicians, reporting in ARPR terms situates outcomes in a methodologically appropriate frame rather than borrowing metrics designed for cycles that involve no physiological insight into timing.

When comparing restorative reproductive medicine outcomes to those reported for IVF, the ARPR is one marker of the difference in starting assumptions. IVF per-embryo-transfer rates reflect a process that bypasses the need for cycle knowledge entirely. The ARPR reflects what is possible when the cycle is understood, respected, and used as both a diagnostic map and a timing guide. These are different questions, and the metrics measure different things.

This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.