Rare ectopic pregnancies after in-vitro fertilization: one unilateral twin and four bilateral tubal pregnancies.

Between 1985 and 1989, one unilateral twin and four bilateral tubal pregnancies were encountered among 124 extrauterine pregnancies and 1648 intrauterine pregnancies following in-vitro fertilization and embryo transfer. The two factors associated with this high incidence of single and multiple extrauterine pregnancies were tubal damage and multiple embryo transfer. Embryos at different stages of development appear to have the capacity to implant ectopically. Despite advances in diagnostic capabilities, ectopic pregnancy remains a major cause of maternal mortality. Early diagnosis prior to rupture must be made if mortality and morbidity are to be abolished. The use of transvaginal sonography has improved the diagnosis of ectopic pregnancy and should be routinely used in all pregnancies following assisted conception. The identification of an intrauterine pregnancy should not be sufficient to rule out the possibility of an extrauterine pregnancy or even bilateral tubal pregnancies.