Preclinical, clinical, and over-the-counter postmarketing experience with a new vaginal cup: menstrual collection

Abstract

Background: Menstrual cups have been available for decades, but their use is limited by bulky design and the need for multiple sizes. The Softcup® (Instead, Inc., San Diego, CA) is a simple single-size disposable over-the-counter (OTC) menstrual cup that compresses to tampon shape to facilitate insertion and can be worn during coitus. This report describes preclinical evaluation, clinical testing, and postmarketing monitoring of the Softcup.

Methods: Preclinical testing complied with U.S. Food and Drug Administration (FDA) guidelines and used standard United States Pharmacopoeia methodologies for assessment of potential toxicity. Clinical testing enrolled 406 women in seven U.S. centers. A detailed written questionnaire assessed safety, acceptability, and effectiveness for menstrual collection. Study safety parameters included pelvic examinations, Pap smears, colposcopy, urinalysis, vaginal pH, wet mounts, gram stain, and vaginal microflora cultures. Postmarketing surveillance of over 100 million Softcups has been conducted by the manufacturer and by the FDA Medwatch system.

Results: No toxicity or mutagenicity was observed in preclinical evaluations. In clinical testing, after three cycles of cup use, 37% of subjects rated the cup as better than, 29% as worse than, and 34% as equal to pads or tampons. The cup was preferred for comfort, dryness, and less odor. Cups received lower ratings for disposal and convenience. Eighty-one percent of enrolled women were able to insert and remove their first cup using only written instructions. Use difficulties resulting in study discontinuations included cramping (1%), leakage (1%), and improper fit (3%). No safety parameters were adversely affected. No significant health risks were reported during postmarketing surveillance.

Conclusions: These results demonstrate that a single-size vaginal device has no significant health risks and is acceptable to many women without the need for fitting or other medical services.

Figures

FIG. 1.

(A) Drawing of the Hockert Catamenial Sack from patent 70,865 in 1867. (B) Drawing of first commercial menstrual cup by Leona Chalmers from patent 2,089,113 in 1937. (C) Photograph of the Instead Softcup® (Instead, Inc., San Diego, CA).

FIG. 2.

Cup performance vs. other methods after each cycle of use, with percent of women rating cup better or worse than current method; the rest of the women rated it the same.

FIG. 3.

Frequency of microorganism recovered after use of the Softcup. The only significant changes were an increase in Enterococcus from month 2 to 3 (p = 0.03) and a decrease in yeast from month 1 to 2 (p = 0.001) using Mantel Haenzel chi-square or Fisher's exact test.

FIG. 4.

Total Softcup complaints reported to the company for 2003–2008.