Delayed Rupture Syndrome (DRS)

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

Delayed Rupture Syndrome (DRS) is a sonographic ovulation disorder, developed and formalized by Dr. Thomas W. Hilgers within NaProTechnology, in which the dominant follicle collapses later than the timing of the woman's charted Peak Day observation would predict.¹ Rather than rupturing in close proximity to Peak Day, the follicle persists for a measurable interval beyond the expected window before eventually collapsing.

Serial ultrasound across the periovulatory window is required to identify the pattern. The follicle is present and morphologically mature on the scan preceding expected ovulation, then documents delayed collapse on a later scan. DRS is distinct from Luteinized Unruptured Follicle Syndrome, in which no rupture occurs at all, and from Partial Rupture Syndrome, in which the follicle partially collapses but fails to complete. In DRS, rupture does eventually occur, but at a time that diverges from the Peak Day signal.

The clinical consequence is a timing mismatch. Couples timing intercourse based on Peak Day are directing that effort toward a window that does not align with actual ovulation. Apparent regularity on the chart does not signal normal ovulatory timing. DRS is classified within Hilgers' sonographic classification of ovulation disorders and carries implications for periovulatory hormonal function, including the LH surge and subsequent corpus luteum quality.

Identifying DRS requires a follicle maturation study. The diagnosis cannot be made from chart data alone. Restorative evaluation targets the underlying endocrine mechanism so that the timing of actual ovulation can be correlated with fertile-phase observations and, where indicated, addressed through appropriate NaProTechnology-based ovulation support.

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.