Romero R, Kadar N, Copel J A, Jeanty P, DeCherney A H, Hobbins J C
Am J Obstet Gynecol. 1985 Sep 1;153(1):72-4. doi: 10.1016/0002-9378(85)90593-9.
The distribution of human chorionic gonadotropin levels in 184 patients with ectopic pregnancy is examined. The impact of changing the sensitivity of human chorionic gonadotropin testing on the incidence of false negative results is discussed. Pregnancy blood tests with a detection threshold of 200 mIU/ml were associated with an 11.9% incidence of false negative results.