Analysis of the incidence and risk factors associated with ectopic pregnancy following in-vitro fertilization and embryo transfer

Ectopic pregnancy is a well known complication of in-vitro fertilization (IVF) and embryo transfer. From March 1983 to December 1993, 3000 clinical pregnancies were achieved at Bourn Hall Clinic, including 135 ectopic pregnancies (4.5%). Of these ectopics 20 were heterotopic, eight ovarian, six bilateral tubal and the remainder were singleton tubal pregnancies. The main risk factor identified in the series was a history of pelvic inflammatory disease (P < 0.001). The data also showed that ectopic pregnancy is at present more prevalent among patients in whom tubal damage is the reason for treatment. There was slight statistical evidence (P = 0.05) that patients having ectopic pregnancies received a higher volume of culture medium than those having normal deliveries. There was also an apparent trend (P = 0.07, not significant) that high progesterone/oestradiol ratio on the day of embryo transfer was associated with ectopic pregnancy. There was no statistical evidence of association between ectopic pregnancy and a history of ectopic pregnancy, abortion, still birth, termination of pregnancy, neonatal death, tubal surgery, ovarian stimulation protocol, plasma concentration of oestradiol, luteinizing hormone and progesterone, number of oocytes retrieved, number or quality of embryos transferred, administration of general anaesthesia for embryo transfer, and the number of patent Fallopian tubes. Awareness of the risk factors associated with ectopic pregnancy plays an important part in the early diagnosis of this potentially fatal condition.