Not Cleared Post-NSE

DEN170052 - Natural Cycles (FDA 510(k) Clearance)

Class II Obstetrics & Gynecology device cleared through the Post-NSE 510(k) pathway - typically does not require clinical trials.

DEN170052 · Natural Cycles Nordic AB · Obstetrics & Gynecology device
Download Printable Device Report (PDF)
Optimized for regulatory review, auditing and printing
Aug 2018
Decision
324d
Days
Class 2
Risk

DEN170052 is an FDA 510(k) submission (not cleared) for the Natural Cycles. Classified as Device, Fertility Diagnostic, Contraceptive, Software Application (product code PYT), Class II - Special Controls.

Submitted by Natural Cycles Nordic AB (Stockholm, SE). The FDA issued a Not Cleared (DENG) decision on August 10, 2018 after a review of 324 days.

This device falls under the Obstetrics & Gynecology FDA review panel, regulated under 21 CFR 884.5370 - the FDA obstetrics and gynecology device framework. The Traditional 510(k) pathway requires demonstration of substantial equivalence to a legally marketed predicate device - a standard the FDA determined was not met in this submission.

Device pattern: Regulatory edge-case submission. High predicate equivalence gap. With 324 days under review and no clearance granted, this submission reflects a case where the FDA could not confirm sufficient predicate equivalence - often indicating either a novel device category or unresolved safety and performance questions.

View all Natural Cycles Nordic AB devices

Submission Details

510(k) Number DEN170052 FDA.gov
FDA Decision Not Cleared Not Substantially Equivalent (DENG)
Date Received September 20, 2017
Decision Date August 10, 2018
Days to Decision 324 days
Submission Type Post-NSE
Review Panel Obstetrics & Gynecology (OB)
Summary -
Third-party Review No - reviewed directly by FDA
Regulatory Context
Review time vs. panel average
164d slower than avg
Panel avg: 160d · This submission: 324d
Pathway characteristics

Device Classification

Product Code PYT Device, Fertility Diagnostic, Contraceptive, Software Application
Device Class Class 2 - Special Controls
CFR Regulation 21 CFR 884.5370
Definition Designed To Monitor And Provide Fertility Information To Prevent Pregnancy (contraception).
What this classification means

Class II devices require demonstration of substantial equivalence to a legally marketed predicate device. This pathway does not require clinical trials - it relies on engineering equivalence and performance data. Most Obstetrics & Gynecology devices follow this clearance model.

Regulatory Peers - PYT Device, Fertility Diagnostic, Contraceptive, Software Application

Devices cleared under the same product code (PYT) and FDA review panel - the closest regulatory comparables to DEN170052.
Natural Cycles
K250561 · Natural Cycles Nordic AB · Mar 2025
Natural Cycles
K241006 · Natural Cycles Nordic AB · Jul 2024
Natural Cycles
K231274 · Natural Cycles Nordic AB · Aug 2023
Natural Cycles
K202897 · Natural Cycles Nordic AB · Jun 2021
Clue Birth Control
K193330 · Biowink GmbH · Feb 2021