Considerations for Identifying Ectopic Pregnancy

If there is an absence of chorionic villi in the pathologic specimen, then one can reasonably diagnose an ectopic pregnancy in the presence of other indicators, such as decreasing or inappropriately increasing quantitative human chorionic gonadotropin levels, even in the absence of diagnostic ultrasonographic findings. Assisted reproductive technologies increase the risk of hetero-topic pregnancy, although likely less than the 1% rate observed in a 1993 Danish survey.1 A more recent analysis of all registered assisted reproductive technology pregnancies in the United States from 1999 to 2002 reported an incidence of heterotopic pregnancy of 1.5 per 1,000 assisted reproductive technology pregnancies, or 0.15%.2 Nevertheless, we agree that clinicians must be aware of this possibility when treating a patient with a pregnancy of unknown location. Furthermore, the absence of chorionic villi does not confirm an ectopic pregnancy because false-negative results are common; chorionic villi are not detected by histopathology in up to 20% of curettage specimens from elective termination of pregnancy.3 Finally, with the advent of methotrexate as a treatment option for suspected ectopic pregnancy, women can now routinely avoid the possibility of undergoing an invasive exploratory laparoscopic procedure, or even a less invasive curettage.