Amazon has shut down a four-year-old secret program working on a fertility monitoring device and accompanying smartphone app, CNBC reported.

The project, which was known by the codename “Encore,” evolved out of Amazon’s 2020 purchase of a startup called bluDiagnostics, which was developing a device that measured the levels of estradiol and progesterone — two of the hormones responsible for fertility in women — from saliva samples.

Amazon planned to release the product this year, but the team of approximately 100 people ran into technical challenges, according to the report. Encore was a part of Amazon’s Grand Challenge initiative, a secretive lab known for taking on bold or moonshot projects like cancer research.

Andy Jassy, the company’s CEO, has been in a cost-cutting mode since 2022. In addition to eliminating 27,000 jobs, he shut down a number of experimental projects, including an AR headset for meetings and a virtual tour product.