The Measurement of Human Chorionic Gonadotropin for Pregnancy Testing

/Among many measurable hormones, human chorionic gonadotropin (FICG) is commonly used for pregnancy testing because it is very sensitive and relatively specific. Pregnancy can be identified shortly after implantation. Because some reagents cross-react with luteinizing hormone (LH), the sensitivity of urine tests has been adjusted to maintain specificity. Radioreceptor assay s on serum are more sensitive than urine tests but similarly lack specificity. The problems of LH cross-reactivity are eliminated by antisera specific for the beta subunit. Quantitation of HCG provides additional information useful in diagnosing ectopic pregnancy, providing a prognosis in threatened abortion, and following neoplasms. Considerations of cost, availability, accuracy, and sensitivity determine which test should be selected