[An evaluation method for the determination and monitoring of urinary HCG]

A kit of anti-beta hCG monoclonal antibodies (Pharmacia beta hCG Riact) has been tested in the assay and monitoring of urinary hCG. After several tests, the technique was found to be reproducible and specific for assay of hCG and showed good sensitivity in urine assays. Optimal sensitivity was seen in the urine pH range 5.5 and 10.00. Below 5.5 and above 10.00, its detection capacity dropped off sharply. Dilution of urine with the kit buffer gave hormonal values comparable to those of undiluted urine, but improved them substantially when the urine pH was below 5.5. It is therefore wise to dilute urine to avoid the potential risk of assay interference by urine acidity. In frozen urine, hCG concentrations tend to decrease but are not altered significantly. This recently developed method allows easy and reliable monitoring of urinary hCG for detection of unknown pregnancy in spontaneous cycles, surveillance of the state of embryos transferred during in vitro fertilization cycles, and evaluation of the efficacy of treatment of tumors secreting (beta hCG).