A novel progesterone delivery system called Callavid is being tested in the UK as a more comfortable alternative to the traditional vaginal pessary used by women at risk of miscarriage. The device, shaped like a tampon, releases 400 mg of progesterone over two hours and is being evaluated in a small trial at University Hospitals Coventry and Warwickshire NHS Trust.

Callavid’s design targets the 10 ml discharge problem

Professor Siobhan Quenby of the University of Warwick explains that many patients experience up to 10 ml of vaginal discharge per dose when using standard pessaries, a side effect that fuels anxiety about losing the hormone dose. Callavid’s organic‑cotton body and external absorbent disc are intended to capture any leakage, potentially eliminating the need for patients to stay supine after insertion.

Trial compares Callavid to standard pessary in 20 women

The ongoing study enrolls 20 participants with luteal phase insufficiency and at least one prior miscarriage. each woman will use Callavid for one week and a conventional 400 mg pessary for another month, with blood tests taken before and after each period to gauge progesterone absorption. according to the trial protocol, comfort questionnaires and pad weight measurements will also quantify leakage.

Previous PRISM findings set efficacy benchmark

The 2019 PRISM study, published in the New England Journal of Medicine, showed that twice‑daily 400 mg pessaries raised live‑birth rates to 72 % for women with three or more miscarriages, compared with 57 % on placebo.. While effective, the study highlighted poor tolerability, a gap Callavid hopes to fill. As the source notes, “the uncertainly about whether the discharge contains the hormone also makes women worry they are not receiving the full dose.”

Potential expansion beyond miscarriage prevention

Manufacturers envision Callavid’s use for other progesterone‑related indications, such as controlling early‑pregnancy bleeding, reducing uterine contractions to prevent preterm birth, and improving embryo implantation in IVF cycles. If the trial demonstrates comparable hormone levels and higher comfort scores, the device could reach the market by the end of next year.

Who will decide if Callavid replaces pessaries?

Funding for the trial comes from the National Institute for Health and Care Research, and the results will inform NHS prescribing guidelines. however, the small sample size leaves open questions about long‑term safety, cost‑effectiveness, and whether the two‑hour release window provides sufficient hormone exposure throughout the day.