Chronic ectopic pregnancy - Two cases of acute rupture despite negative beta HCG

We present the cases of two women with chronic ectopic pregnancies who pres ented with acute tubal rupture and hemoperitoneum despite negative P-human chorionic gonadotropin (beta hCG) pregnancy tests, The appropriate screenin g use of beta hCG assays to ascertain pregnancy status, the mechanisms by w hich ectopic pregnancy may be seen with negative beta hCG tests, and the li mitations of various assays are discussed. One patient, not initially belie ved to be pregnant, underwent computed tomography (CT) scan. Experience wit h use of CT scan in ectopic pregnancy diagnosis is limited; our case illust rates some of the possible CT scan findings. These cases illustrate the pot ential for ectopic pregnancy to rupture with low, if not undetectable beta hCG hormone levels, and consequently why it is not recommended to rely on q uantitative beta hCG levels to guide the decision to proceed with ultrasoun d imaging. (C) 2000 Elsevier Science Inc.