Base Infertile Pattern (BIP)

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

The Base Infertile Pattern (BIP) is the unchanging baseline of vulvar observations recorded by a woman experiencing continuous cervical discharge, used to identify which days are infertile by their sameness and which represent a departure toward fertility.⁷⁹

Many women cannot rely on the simple dry-day rule because they have an ongoing discharge: postpartum, while breastfeeding, in the post-pill transition, during perimenopause, or during anovulatory cycles. The BIP resolves this. Over several consecutive days of identical observations, the woman establishes her personal baseline. That pattern, once documented, defines infertility for her. Any day matching the BIP is infertile. Any departure from the BIP marks the Point of Change and signals the opening of the fertile window.

The BIP approach extends CrMS charting to populations where standard charting rules do not apply, without requiring any internal exam or testing. Instruction by a certified FertilityCare Practitioner is required before applying the BIP.

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.