title: An algorithm for determining gestational age from unconjugated estriol levels.
abstract: Between the 30th and 40th weeks of gestational age (GA), plasma unconjugated estriol (E3) concentrations plotted as a logarithmic function of GA describe a complex bimodal curve. The maximum concentrations for the first peak (GAmax1) occur at approximately 34 weeks' GA, those for the second peak (GAmax2) occur at approximately 38 weeks' GA, and a between-mode nadir occurs at 35 weeks' GA. Using the close relationship between the features of this curve and GA, a computerized algorithmic curve analysis is devised for the estimation of GA during the third trimester of pregnancy. This report describes the algorithm, its clinical application, and its preliminary performance.
mesh_terms: D003201:Computers; D004964:Estriol / Q000097:blood*; D005260:Female; D005865:Gestational Age; D006801:Humans; D008433:Mathematics; D007752:Obstetric Labor, Premature / Q000175:diagnosis; D011247:Pregnancy; D012306:Risk; D013997:Time Factors
chemical_list: D004964:Estriol