Pregnancy of unknown location: Evaluation and management.

Early diagnosis of an extrauterine pregnancy is important for safe and effective management. However, a pregnancy's location often cannot be easily determined with abnormal implantations or prior to 5-6 weeks' gestation. Multiple testing strategies exist to diagnose an abnormal pregnancy when location is unknown, but caution needs to be used to avoid a false diagnosis. Medical treatment is optimal when an abnormal pregnancy is diagnosed early. Because most of these pregnancies are intrauterine, additional testing to localize the pregnancy will allow the correct choice of therapy and avoids unnecessary exposure to a toxic therapy. This testing strategy should be reserved for patients with significant concern for ectopic pregnancy, based on either risk factors or clinical findings. Overuse of this approach can lead to interruption of normal pregnancies.