Preoperative cervical dilatation by vaginal pessaries containing a prostaglandin E1 analogue (gemeprost, Cervagem)

Abstract

Surgical termination of pregnancy by cervical dilatation and suction during the first trimester is a commonly performed operation. The incidence of subsequent mid-trimester abortions due to cervical damage at the time of cervical dilatation has been shown to increase1, particularly in nulliparous patients2. A fast-acting locally administered non-invasive agent, used pre-operatively, which could soften and dilate the cervix should reduce the incidence of cervical damage which, in nulliparous patients, can be as high as 2.7%3. Prostaglandins have been shown to lower the resistance of the cervix to mechanical dilatation4, and to reduce the stretch modulus of human cervical tissue in vitro 5. The mechanism of action may be due to alterations in the composition of collagen ground substance6. Prostaglandin E2 has been used in this role but large doses are required which cause troublesome side-effects7. The intravaginal administration of a potent prostaglandin analogue may be efficacious with an acceptably low incidence of side- effects. This paper reports two studies of the use of a single intravaginal pessary of 16,16-dimethyl-trans-Δ2 PGE1 methyl ester (gemeprost) inserted approximately 3 hours before surgical termination of first trimester pregnancies.