LABORATORY METHODS FOR EVALUATING EARLY-PREGNANCY LOSS IN AN INDUSTRY-BASED POPULATION

Laboratory methods were adapted or developed to analyze approximately 70,000 daily urine samples collected during more than 2,500 menstrual cycles from 448 women working in the semiconductor industry. An immuno enzymometric assay (IEMA) for human chorionic gonadotropin (hCG) was e mployed for screening cycles in order to optimize laboratory resources and to reduce the number of samples requiring analysis by less effici ent methods. The presence of hCG in urine was confirmed by the definit ive immunoradiometric assay (IRMA). The screening assay eliminated 78% of cycles from further analysis because there was no evidence of conc eption. Thirty-eight of 448 cycles identified as having significant le vels of hCG with the LEMA were confirmed as hCG positive with the IRMA . HCG-positive cycles were further evaluated by examination of daily d iary data and by laboratory assays for ovarian and pituitary hormones. As a result of these evaluations, 17 of the 38 cycles identified by t he IRMA as positive for hCG were found to be nonconceptive cycles. The se results demonstrate the effectiveness of screening assays for hCG, as well as the importance of using multiple urinary biomarkers for the detection of early fetal loss with daily urine samples. (C) 1995 Wile y-Liss, Inc.