Here are the highlights from the 2012 ACEP Clinical Policy regarding Critical Issues in the Initial Evaluation and Management of Patients Presenting to the ED in Early Pregnancy:
The initial quantitative BhCG level does not help to distinguish among unspecified abortion (i.e. threatened abortion), normal intrauterine pregnancy, and ectopic pregnancy. Therefore, the discriminatory threshold is no longer utilized in clinical decision-making. Do not let a BhCG level lower than the discriminatory threshold deter you from getting a pelvic US in a symptomatic, unconfirmed early pregnancy. Ectopic pregnancies can present with low, normal and high BhCG levels; ectopic pregnancy ruptures can occur at any BhCG level. Do not let a low BhCG level in the setting of an indeterminate pelvic US provide false reassurance that you have ruled out an ectopic pregnancy.
Rhogam is recommended in Rh negative women with completed abortions (level B recommendation). There is insufficient data to support or refute it’s use in threatened abortions or ectopic pregnancies.
Methotrexate (MTX) is not infallible. Treatment failure after the first dose of MTX is well documented. Some patients require multiple doses of MTX for successful resolution of ectopic pregnancies. Furthermore, patients who have received MTX can still rupture their ectopic pregnancy. Therefore, for patients with confirmed or suspected ectopic pregnancies s/p MTX arrange timely follow-up if stable or rule out ruptured ectopic if unstable.
Strayer R. Rule Out Ectopic in the Emergency Department. EMUpdates.com
Hahn SA. Lavonas EJ. Mace SE. Napoli AM. Fesmire FM. Clinical Policy: Critical Issues in the Initial Evaluation and Management of Patients Presenting to the Emergency Department in Early Pregnancy. Ann Emerg Med. 2012;60:381-390.