NaProTECHNOLOGY uses the Peak Day of the Creighton Model chart — the last day of the most fertile-type cervical mucus — as the reference point for dating conception, providing a biologically grounded alternative to last menstrual period dating that remains accurate across irregular cycles. Precise cycle-based dating improves the clinical interpretation of early pregnancy hormone levels, ultrasound findings, and obstetric gestational age assignments, reducing unnecessary interventions triggered by apparent growth discordance.
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Hilgers et al. 2004, Hilgers 2004
Cite this article
Hilgers, T. W. (2004). Chapter 53: Dating the Beginning of Pregnancy. The Medical and Surgical Practice of NaProTECHNOLOGY, 707-712.
Hilgers TW. Chapter 53: Dating the Beginning of Pregnancy. The Medical and Surgical Practice of NaProTECHNOLOGY. 2004:707-712.
Hilgers, T. W. "Chapter 53: Dating the Beginning of Pregnancy." The Medical and Surgical Practice of NaProTECHNOLOGY, 2004, pp. 707-712.
Hilgers TW, 2004·The Medical and Surgical Practice of NaProTECHNOLOGY
The CrMS charting system is explained in full, including the stamp-based notation for recording mucus characteristics, bleeding, and dry days on the standardized chart, and the conventions for identifying the Peak Day. Accurate chart reading is the foundational clinical skill for NaProTECHNOLOGY practitioners, as the chart provides the biomarker timeline against which hormone profiles and pathology are interpreted.
Hilgers TW, 2004·The Medical and Surgical Practice of NaProTECHNOLOGY
Women with persistent or continuous vaginal discharges — including those from chronic cervicitis, hormonal imbalance, or other gynecologic sources — present a distinct charting challenge, and this chapter provides CrMS-specific protocols for distinguishing pathologic discharge from fertile-quality cervical mucus. Correct identification is clinically critical because misclassification distorts cycle interpretation, effectiveness calculations, and the hormone-assessment timeline.
Hilgers TW, 2004·The Medical and Surgical Practice of NaProTECHNOLOGY
This 2004 textbook chapter by Thomas W. Hilgers outlines the structure and content of the formal introductory session used to enroll couples in the Creighton Model FertilityCare System (CrMS). It covers the biological foundation of fertility charting, the role of cervical mucus as a biomarker of the reproductive cycle, and the educational framework designed to train couples in systematic, real-time cycle observation.
Hilgers TW, 2004·The Medical and Surgical Practice of NaProTECHNOLOGY
The Creighton Model FertilityCare System (CrMS) is introduced as a standardized, scientifically grounded method for observing and recording cervical mucus biomarkers and bleeding patterns across the menstrual cycle. Its development from earlier natural family planning methods into a fully systematized fertility monitoring tool is traced, establishing the CrMS as the observational substrate for all subsequent NaProTECHNOLOGY medical applications.