Urea-prostaglandin versus hypertonic saline for instillation abortion.

Authorities have suggested use of a combination of hyperosmolar urea and low-dose prostaglandin F2 alpha as a second-trimester intra-amniotic abortifacient to avoid the disadvantages of hypertonic saline solution. To examine the safety and efficacy of urea-prostaglandin compared with the instillation of saline solution, we analyzed data from a prospective multicenter study conducted in the United States between 1975 and 1978. Both agents were highly effective in producing an abortion. However, urea-prostaglandin had a significantly lower rate of serious complications when compared with saline solution (1.03 versus 2.18 per 100 abortions; p less than 0.001). Urea-prostaglandin also had a significantly shorter induction-to-abortion time (14.2 versus 25.6 hours; p less than 0.001). Urea-prostaglandin, therefore, appears to be superior to hypertonic saline solution as an abortifacient.