The prediction of ectopic pregnancy after in-vitro fertilization and embryo transfer

Data from 135 patients who suffered ectopic pregnancies and from 135 patients who progressed to singleton deliveries after in-vitro fertilization and embryo transfer have been analysed retrospectively. The ectopic pregnancies represent all such cases observed at Bourn Hall Clinic between 1983 and 1993. The delivered group was randomly selected from the same time period. The ectopic pregnancies included 20 heterotopic, eight ovarian and six bilateral tubal pregnancies; the remainder were singleton tubal pregnancies. The aim of this study was to identify the variables which differed systematically for the two groups of patients and to explore whether such variables could be used to predict ectopic pregnancy at an early stage. The mean plasma concentration of human chorionic gonadotrophin and progesterone for the ectopic pregnancy group was significantly lower than that for the singleton delivery group (P < 0.001). However, there was such a degree of overlap that it was impossible to devise a cut-off concentration for either hormone which would offer a clinically useful predictor of ectopic pregnancy. Nevertheless, using the discriminant function analysis of these data, together with the history of pelvic inflammatory disease, we could predict up to 90% of cases of ectopic pregnancy by day 23 after embryo transfer, long before ultrasound imaging would be useful.