RESUMEN
A prospective, randomized controlled study was made to measure the circulating levels of 13, 14-dihydro-15-keto-prostaglandin F (PGFM) in two groups of women having cervical cerclage early in the second trimester of pregnancy. One group of patients was given omnopon by intramuscular injection for 24 hours after operation and the other salbutamol by intravenous infusion. A significant rise in circulating PGFM was found in both groups after cervical cerclage and the magnitude of the rise was similar in the two groups; levels of PGFM in both groups had returned to the preoperative levels within 24 hours of operation. The levels of PGFM before and after operation showed no relation to the eventual outcome of the pregnancy, which was successful in 80 percent of patients.