Achieving-Related Pregnancy Rate (ARPR)

By RRM Academy Reviewed by Dr. Naomi Whittaker, MD, Board-Certified OBGYN, MIGS, NFPMC, FCI Updated May 7, 2026

The Achieving-Related Pregnancy Rate (ARPR) is a CrMS use-effectiveness statistic that measures pregnancy outcomes in couples who intentionally shift from avoiding to achieving conception, calculated using Hilgers' life-table adaptation of the Tietze-Lewit framework. The foundational dataset includes a five-study composite of 1,876 couples across 17,130.5 couple-months.⁷⁸⁸³

The ARPR is methodologically distinct from generic cumulative pregnancy rates. Most fertility effectiveness statistics count all exposure cycles, regardless of whether the couple was timing intercourse to achieve or avoid. The ARPR isolates fertility-focused intercourse cycles identified via Peak Day timing on the Creighton Model chart. It then calculates conception probability within 12 ordinal months. The denominator is controlled for intent and method use.

This distinction matters clinically. A couple using fertility-focused intercourse timed to the fertile window is not statistically comparable to a couple having intercourse without cycle awareness. The ARPR accounts for this. It is the foundational effectiveness measure underlying CrMS achieving outcomes data and is cited in Hilgers' treatment outcome analyses for conditions including luteal phase deficiency and endometriosis-related subfertility.

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.