Evaluation of a urinary test as a diagnostic tool of a nonprogressive pregnancy.

OBJECTIVE

To evaluate the performance of a one-step test detecting intact hCG and free β-hCG isoforms in the urine of pregnant women to diagnose an abnormal pregnancy.

DESIGN

Prospective study.

SETTING

Emergency gynecology departments in teaching hospitals.

PATIENT(S): Five hundred twenty-six patients were enrolled, 272 who were not pregnant and 254 who were pregnant.

INTERVENTION(S) AND MAIN OUTCOME MEASURE(S): Semiquantitative determination of intact urinary hCG of supposedly not pregnant and pregnant women with vaginal bleeding and/or vaginal pain between 5 and 8 weeks of amenorrhea.

RESULT(S): The sensitivity and specificity of the urine test for diagnosing nonpregnancy were, respectively, 100% (252/252) and 100% (272/272). The sensitivity and specificity of the urine test for diagnosing ectopic pregnancy (EP) were, respectively, 97% (32/33) and 83% (142/171). The negative predictive value is 99.3% (142/143). The sensitivity and specificity or the urine test for diagnosing miscarriage were, respectively, 89.6% (43/48) and 83% (142/171). The negative predictive value is 96.6% (142/147).

CONCLUSION(S): Abnormal pregnancy, such as an EP or a miscarriage, can be rapidly detected with the one-step test for intact hCG and free β-hCG isoforms. If ultrasound cannot confirm the localization and/or evolution of a pregnancy, using this test reduces medical supervision and repeated quantification of hCG.