Abstract In normal pregnancy, the cervix remains closed until term and then dilates under the influence of uterine contractions. In cases of cervical insufficiency (CI), the cervix dilates in the second trimester in the absence of uterine contractions, which leads to a preterm birth. Infants born prematurely are at risk of lifelong morbidities including chronic lung disease, feeding difficulties, retinopathy and neurodevelopmental abnormalities. Cervical cerclage is the current treatment for cervical insufficiency. Cerclage surgery is performed in 15,000 cases per year in the United States. A cerclage is a surgical suture that is placed around the cervix to provide mechanical support. Though cerclage suture can prevent preterm birth in women with CI, cerclage has important limitations and can lead to adverse events. A team of leading researchers and practitioners at Tufts Medical Center is developing a new technology that addresses the shortcomings of the current cerclage suture. Referred to in this proposal as the cervical support device (CSD), the new technology rethinks the challenge of providing mechanical support for the cervix. The CSD preserves compression support of the cerclage suture but spreads the compression support over a wider surface area, which alleviates excess stress concentrations and decreases adverse effects. The CSD also permits adjustable compression support over time, which is an innovative feature not available with cerclage. Cx Therapeutics was founded to further develop and commercialize this innovative medical device for CI. The studies proposed in this STTR Phase I project will determine the functional feasibility of the CSD versus cerclage in bench top and animal testing (Aim 1). Aim 2 will establish the foundation of engineering development through a partnership with a leading and highly experienced medical device developer. Proof-of-principle devices will be developed for testing in a formative human factors study (Aim 3). At the end of Phase I, Cx Therapeutics will have developed a prototype CSD with novel features and an improved safety profile compared with existing cerclage suture. In Phase II, detailed engineering design will occur, further testing on animal models and activities will be organized around assembling a package of materials for a pre-market submission to the FDA. The long-term goal is to compare the CSD to cerclage suture in a randomized clinical trial for women with cervical insufficiency. The randomized trial will test the hypothesis that the CSD will prolong pregnancy and will cause fewer adverse effects compared with cerclage. The development of an effective alternative treatment for cervical insufficiency will have an enormous impact in clinical obstetrics.