Prevention of Preterm Birth With a Pessary in Twin Gestations

Preterm birth (PTB) is a major health problem and contributes to more than 50% of the overall
perinatal mortality. Twins are at increased risk for PTB. The number of twins births has
risen substantially due to the increased use of assisted reproductive technology. The rate of
twin births in the United States rose from 18.9 to 32.2 per 100 live births between 1980 and
2004. The increased rate of PTB in twins is associated with increased morbidity and mortality
rates. Almost one in four very low birth-weight infants (below 1500 g) born in the United
States are twins, as are one in six infants who die in the first month of life. Cervical
shortening is a risk factor for PTB. Transvaginal ultrasound measurement of cervical length
is a reliable screening test for prediction of PTB. There is currently no effective treatment
to decrease the incidence of PTB in women with twin gestations, but there is some evidence
that the use of a cervical pessary in women with a short cervix has promise. If effective
this approach would be particularly appealing because of the wide availability of pessaries,
ease of use, and low cost. Unfortunately, existing studies are inadequate to confirm
effectiveness; a well designed, properly powered, prospective randomized trial is warranted
prior to widespread implementation in clinical practice. We propose such a trial to study the
effectiveness of the pessary in decreasing the incidence of PTB in an inner city Philadelphia
population.