PREDICTION OF PERSISTENT TROPHOBLASTIC ACTIVITY AFTER LOCAL PROSTAGLANDIN-F2-ALPHA INJECTION FOR ECTOPIC PREGNANCY

A total of 60 patients underwent injection of prostaglandin (PG)F-2 al pha into the affected tube and corpus luteum. Two serum samples, with a mean interval of 2.1 days, were taken pre-operatively and human chor ionic gonadotrophin (HCG) and progesterone were determined by fluoroim munoassay retrospectively. Cases requiring a second intervention (n = 8) were compared with uncomplicated cases (n = 52). The receiver-opera tor characteristic curve was used to determine optimal discriminatory levels of each diagnostic test. Among the complicated cases, 75% had p rogesterone values >20 nmol/l and 100% had a daily HCG increase >50 IU /l. The corresponding figures for the uncomplicated cases were 17% and 23% respectively. A 'high-risk' group representing 12% of the patient material was identified, and was biochemically profiled by serum prog esterone values >20 nmol/l, together with daily HCG changes > +50 IU/l /day. These patients had an 86% risk for a second intervention. Conver sely, 88% of patients had only a 4% risk for such an intervention. We conclude that the combined use of two sequential serum HCG samples and one serum progesterone sample, the last of each taken not more than 2 4 h pre-operatively, can predict the risk for a complicated course fol lowing local injection of 15-methyl-PGF(2 alpha) for small tubal pregn ancies.