The radioreceptor assay for hCG in ectopic pregnancy.

The Biocept-G test (Wampole) is a commercial modification of the radioreceptor assay for human chorionic gonadotropin (hCG) which takes 1 hours to process and has a sensitivity of 200 mIU/ml for hCG. Over a 9 1/2-month period, 70 consecutive patients with proven ectopic pregnancy were evaluated by the Biocept-G test, 2-minute urine slide test, and culdocentesis. Of 67 of these patients, 94% had a positive Biocept-G test, 82% had a positive culdocentesis, and 69% had a positive urine slide test. Sixty-nine (97%) of the 70 patients had either a positive Biocept-G and/or a positive culdocentesis, while only 1.7% had both a negative culdocentesis and a negative Biocept-G. Thirty-two patients underwent laparoscopy or laparotomy during this time period to rule out ectopic pregnancy but were not found to have this condition. The Biocept-G had a 94% accuracy rate in determining the presence or absence of intrauterine pregnancy in this group, compared to an 82% accuracy rate for the urine slide test. The Biocept-G has the highest true-positive rate for ectopic pregnancy published to date for a rapidly performed, commercially available pregnancy test.