An evaluation of four serum tests for pregnancy.
We evaluated four pregnancy tests (Biocept-G, Beta-CG, Preg/Stat, and HCG-Beta Screen), using sera from 59 nonpregnant subjects and 77 patients with serum human choriogonadotropin beta-subunit (beta-hCG) concentrations ranging from 4 to 100 000 int. units/L. The results obtained for each test were compared with the results predicted on the basis of the sample's beta-hCG concentration and the beta-hCG concentration the manufacturer claimed necessary for a positive result (the test's analytical sensitivity). Biocept-G had the best sensitivity (100%), specificity (98.9%), and accuracy (99.2%). Beta-CG had the poorest sensitivity (86.4%), Preg/Stat the poorest specificity (87.5%), and accuracy (92.6%). We confirmed the manufacturer's claimed analytical sensitivity (200 int. units/L) for the Biocept-G procedure, but our calculated analytical sensitivity for the other tests was significantly different from that claimed by their manufacturers. Best results were obtained with Biocept-G, but with its analytical sensitivity of 200 int. units/L, samples from early pregnancy will give negative results. None of the pregnancy tests evaluated here will establish the presence or absence of early pregnancy with certainty.
D006063:Chorionic Gonadotropin / Q000097:blood*; D005260:Female; D006801:Humans; D011258:Pregnancy Tests / Q000379:methods*; D011863:Radioimmunoassay / Q000379:methods; D011933:Reagent Kits, Diagnostic; D011956:Receptors, Cell Surface / Q000032:analysis*; D011974:Receptors, LH; D013223:Statistics as Topic; D013997:Time Factors
D006063:Chorionic Gonadotropin; D011933:Reagent Kits, Diagnostic; D011956:Receptors, Cell Surface; D011974:Receptors, LH