The objective of this study was to evaluate a progesterone cutpoint of 5.0 ng/mL ability to identify abnormal pregnancy (abnormal intrauterine pregnancy and ectopic pregnancy) as well as ectopic pregnancy alone in 2 subclasses of indeterminate ultrasounds. This was a prospective observational study of emergency department patients with abdominal pain or vaginal bleeding and an indeterminate transvaginal ultrasound. Two subclasses of indeterminate ultrasounds were eligible: those with an empty uterus and a beta-human chorionic gonadotropin value <3,000 mIU/mL and those with a nonspecific fluid collection. Patients were enrolled if a progesterone assay was collected the day of the emergency department visit. Patients were excluded if lost to follow-up. One hundred sixty patients were enrolled. Of these, 24 were diagnosed with ectopic pregnancy. The sensitivity and specificity of progesterone identifying abnormal pregnancy were 84% and 97%, respectively. The sensitivity and specificity of progesterone identifying ectopic pregnancy were 88% and 40%, respectively. In the 2 subclasses, the progesterone cutpoint was both sensitive and specific in identifying abnormal pregnancy and was sensitive but only moderately specific for identifying ectopic pregnancy.
Copyright 2002, Elsevier Science (USA). All rights reserved.)