Adolescent pregnancy testing: which test to use

In order to study the sensitivity and efficiency of five pregnancy tests, we evaluated four types of urine tests in 162 adolescent girls in whom pregnancy was suspected; a serum test was performed in 46 of them. We found that (1) an increase in sensitivity occurred at the expense of specificity, (2) the quantitation of the beta-subunit of human chorionic gonadotropin in serum proved to be the most reliable test for pregnancy, and (3) the latex agglutination inhibition tube test (Placentex) was the most accurate of the four types of urine tests evaluated. We concluded that for adolescents, the serum pregnancy test is the preferred test, but when it is not available, the urine latex agglutination inhibition tube test offers the most reliable alternative.